diff --git a/AK/Platform.h b/AK/Platform.h
index 1000e7f4724..2aefdda7122 100644
--- a/AK/Platform.h
+++ b/AK/Platform.h
@@ -276,11 +276,13 @@
 #    define ASAN_UNPOISON_MEMORY_REGION(addr, size) __asan_unpoison_memory_region(addr, size)
 #    define LSAN_REGISTER_ROOT_REGION(base, size) __lsan_register_root_region(base, size)
 #    define LSAN_UNREGISTER_ROOT_REGION(base, size) __lsan_unregister_root_region(base, size)
+#    define LSAN_IGNORE_OBJECT(base) __lsan_ignore_object(base)
 #else
 #    define ASAN_POISON_MEMORY_REGION(addr, size)
 #    define ASAN_UNPOISON_MEMORY_REGION(addr, size)
 #    define LSAN_REGISTER_ROOT_REGION(base, size)
 #    define LSAN_UNREGISTER_ROOT_REGION(base, size)
+#    define LSAN_IGNORE_OBJECT(base)
 #endif
 
 #if __has_feature(blocks)
diff --git a/Libraries/LibGC/CMakeLists.txt b/Libraries/LibGC/CMakeLists.txt
index c89319960ad..378f0790b52 100644
--- a/Libraries/LibGC/CMakeLists.txt
+++ b/Libraries/LibGC/CMakeLists.txt
@@ -9,6 +9,7 @@ set(SOURCES
     RootVector.cpp
     Heap.cpp
     HeapBlock.cpp
+    WeakBlock.cpp
     WeakContainer.cpp
 )
 
diff --git a/Libraries/LibGC/Forward.h b/Libraries/LibGC/Forward.h
index b531242a68e..ddf12dc528a 100644
--- a/Libraries/LibGC/Forward.h
+++ b/Libraries/LibGC/Forward.h
@@ -20,6 +20,7 @@ class Heap;
 class HeapBlock;
 class NanBoxedValue;
 class WeakContainer;
+class WeakImpl;
 
 template<typename T>
 class Function;
diff --git a/Libraries/LibGC/Heap.cpp b/Libraries/LibGC/Heap.cpp
index 0c258537781..fe661af0068 100644
--- a/Libraries/LibGC/Heap.cpp
+++ b/Libraries/LibGC/Heap.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2020-2022, Andreas Kling <andreas@ladybird.org>
+ * Copyright (c) 2020-2025, Andreas Kling <andreas@ladybird.org>
  * Copyright (c) 2023, Aliaksandr Kalenik <kalenik.aliaksandr@gmail.com>
  *
  * SPDX-License-Identifier: BSD-2-Clause
@@ -20,6 +20,8 @@
 #include <LibGC/HeapBlock.h>
 #include <LibGC/NanBoxedValue.h>
 #include <LibGC/Root.h>
+#include <LibGC/Weak.h>
+#include <LibGC/WeakInlines.h>
 #include <setjmp.h>
 
 #ifdef HAS_ADDRESS_SANITIZER
@@ -258,6 +260,7 @@ void Heap::collect_garbage(CollectionType collection_type, bool print_report)
             mark_live_cells(roots);
         }
         finalize_unmarked_cells();
+        sweep_weak_blocks();
         sweep_dead_cells(print_report, collection_measurement_timer);
     }
 
@@ -462,6 +465,22 @@ void Heap::finalize_unmarked_cells()
     });
 }
 
+void Heap::sweep_weak_blocks()
+{
+    for (auto& weak_block : m_usable_weak_blocks) {
+        weak_block.sweep();
+    }
+    Vector<WeakBlock&> now_usable_weak_blocks;
+    for (auto& weak_block : m_full_weak_blocks) {
+        weak_block.sweep();
+        if (weak_block.can_allocate())
+            now_usable_weak_blocks.append(weak_block);
+    }
+    for (auto& weak_block : now_usable_weak_blocks) {
+        m_usable_weak_blocks.append(weak_block);
+    }
+}
+
 void Heap::sweep_dead_cells(bool print_report, Core::ElapsedTimer const& measurement_timer)
 {
     dbgln_if(HEAP_DEBUG, "sweep_dead_cells:");
@@ -559,4 +578,21 @@ void Heap::uproot_cell(Cell* cell)
     m_uprooted_cells.append(cell);
 }
 
+WeakImpl* Heap::create_weak_impl(void* ptr)
+{
+    if (m_usable_weak_blocks.is_empty()) {
+        // NOTE: These are leaked on Heap destruction, but that's fine since Heap is tied to process lifetime.
+        auto* weak_block = WeakBlock::create();
+        m_usable_weak_blocks.append(*weak_block);
+    }
+
+    auto* weak_block = m_usable_weak_blocks.first();
+    auto* new_weak_impl = weak_block->allocate(static_cast<Cell*>(ptr));
+    if (!weak_block->can_allocate()) {
+        m_full_weak_blocks.append(*weak_block);
+    }
+
+    return new_weak_impl;
+}
+
 }
diff --git a/Libraries/LibGC/Heap.h b/Libraries/LibGC/Heap.h
index 193ce4ecc13..91b15c4c7fd 100644
--- a/Libraries/LibGC/Heap.h
+++ b/Libraries/LibGC/Heap.h
@@ -25,6 +25,7 @@
 #include <LibGC/Root.h>
 #include <LibGC/RootHashMap.h>
 #include <LibGC/RootVector.h>
+#include <LibGC/WeakBlock.h>
 #include <LibGC/WeakContainer.h>
 
 namespace GC {
@@ -81,6 +82,8 @@ public:
 
     void enqueue_post_gc_task(AK::Function<void()>);
 
+    WeakImpl* create_weak_impl(void*);
+
 private:
     friend class MarkingVisitor;
     friend class GraphConstructorVisitor;
@@ -113,6 +116,7 @@ private:
     void mark_live_cells(HashMap<Cell*, HeapRoot> const& live_cells);
     void finalize_unmarked_cells();
     void sweep_dead_cells(bool print_report, Core::ElapsedTimer const&);
+    void sweep_weak_blocks();
 
     ALWAYS_INLINE CellAllocator& allocator_for_size(size_t cell_size)
     {
@@ -159,6 +163,9 @@ private:
     AK::Function<void(HashMap<Cell*, GC::HeapRoot>&)> m_gather_embedder_roots;
 
     Vector<AK::Function<void()>> m_post_gc_tasks;
+
+    WeakBlock::List m_usable_weak_blocks;
+    WeakBlock::List m_full_weak_blocks;
 } SWIFT_IMMORTAL_REFERENCE;
 
 inline void Heap::did_create_root(Badge<RootImpl>, RootImpl& impl)
diff --git a/Libraries/LibGC/Weak.h b/Libraries/LibGC/Weak.h
new file mode 100644
index 00000000000..b1d9a60eedf
--- /dev/null
+++ b/Libraries/LibGC/Weak.h
@@ -0,0 +1,166 @@
+/*
+ * Copyright (c) 2025, Andreas Kling <andreas@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Badge.h>
+#include <AK/RefPtr.h>
+#include <LibGC/Export.h>
+#include <LibGC/Ptr.h>
+
+namespace GC {
+
+class WeakBlock;
+
+class WeakImpl {
+public:
+    // NOTE: Null GC::Weaks point at this WeakImpl. This allows Weak to always chase the impl pointer without null-checking it.
+    static GC_API WeakImpl the_null_weak_impl;
+
+    WeakImpl() = default;
+    WeakImpl(void* ptr)
+        : m_ptr(ptr)
+    {
+    }
+
+    void* ptr() const { return m_ptr; }
+    void set_ptr(Badge<WeakBlock>, void* ptr) { m_ptr = ptr; }
+
+    bool operator==(WeakImpl const& other) const { return m_ptr == other.m_ptr; }
+    bool operator!=(WeakImpl const& other) const { return m_ptr != other.m_ptr; }
+
+    void ref() const { ++m_ref_count; }
+    void unref() const
+    {
+        VERIFY(m_ref_count);
+        --m_ref_count;
+    }
+
+    size_t ref_count() const { return m_ref_count; }
+
+    enum class State {
+        Allocated,
+        Freelist,
+    };
+
+    void set_state(State state) { m_state = state; }
+    State state() const { return m_state; }
+
+private:
+    mutable size_t m_ref_count { 0 };
+    State m_state { State::Allocated };
+    void* m_ptr { nullptr };
+};
+
+template<typename T>
+class Weak {
+public:
+    constexpr Weak() = default;
+    Weak(nullptr_t) { }
+
+    Weak(T const* ptr);
+    Weak(T const& ptr);
+
+    template<typename U>
+    Weak(Weak<U> const& other)
+    requires(IsConvertible<U*, T*>);
+
+    Weak(Ref<T> const& other);
+
+    template<typename U>
+    Weak(Ref<U> const& other)
+    requires(IsConvertible<U*, T*>);
+
+    template<typename U>
+    Weak& operator=(Weak<U> const& other)
+    requires(IsConvertible<U*, T*>)
+    {
+        m_impl = other.impl();
+        return *this;
+    }
+
+    Weak& operator=(Ref<T> const& other);
+
+    template<typename U>
+    Weak& operator=(Ref<U> const& other)
+    requires(IsConvertible<U*, T*>);
+
+    Weak& operator=(T const& other);
+
+    template<typename U>
+    Weak& operator=(U const& other)
+    requires(IsConvertible<U*, T*>);
+
+    Weak& operator=(T const* other);
+
+    template<typename U>
+    Weak& operator=(U const* other)
+    requires(IsConvertible<U*, T*>);
+
+    T* operator->() const
+    {
+        ASSERT(ptr());
+        return ptr();
+    }
+
+    [[nodiscard]] T& operator*() const
+    {
+        ASSERT(ptr());
+        return *ptr();
+    }
+
+    Ptr<T> ptr() const { return static_cast<T*>(impl().ptr()); }
+
+    explicit operator bool() const { return !!ptr(); }
+    bool operator!() const { return !ptr(); }
+
+    operator T*() const { return ptr(); }
+
+    Ref<T> as_nonnull() const
+    {
+        ASSERT(ptr());
+        return *ptr();
+    }
+
+    WeakImpl& impl() const { return *m_impl; }
+
+private:
+    NonnullRefPtr<WeakImpl> m_impl { WeakImpl::the_null_weak_impl };
+};
+
+template<typename T, typename U>
+inline bool operator==(Weak<T> const& a, Ptr<U> const& b)
+{
+    return a.ptr() == b.ptr();
+}
+
+template<typename T, typename U>
+inline bool operator==(Weak<T> const& a, Ref<U> const& b)
+{
+    return a.ptr() == b.ptr();
+}
+
+}
+
+namespace AK {
+
+template<typename T>
+struct Traits<GC::Weak<T>> : public DefaultTraits<GC::Weak<T>> {
+    static unsigned hash(GC::Weak<T> const& value)
+    {
+        return Traits<T*>::hash(value.ptr());
+    }
+};
+
+template<typename T>
+struct Formatter<GC::Weak<T>> : Formatter<T const*> {
+    ErrorOr<void> format(FormatBuilder& builder, GC::Weak<T> const& value)
+    {
+        return Formatter<T const*>::format(builder, value.ptr());
+    }
+};
+
+}
diff --git a/Libraries/LibGC/WeakBlock.cpp b/Libraries/LibGC/WeakBlock.cpp
new file mode 100644
index 00000000000..5a00dbd7aca
--- /dev/null
+++ b/Libraries/LibGC/WeakBlock.cpp
@@ -0,0 +1,77 @@
+/*
+ * Copyright (c) 2025, Andreas Kling <andreas@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibGC/Cell.h>
+#include <LibGC/WeakBlock.h>
+#include <sys/mman.h>
+
+#if defined(AK_OS_WINDOWS)
+#    include <AK/Windows.h>
+#    include <memoryapi.h>
+#endif
+
+namespace GC {
+
+WeakImpl WeakImpl::the_null_weak_impl;
+
+WeakBlock* WeakBlock::create()
+{
+#if !defined(AK_OS_WINDOWS)
+    auto* block = (HeapBlock*)mmap(nullptr, WeakBlock::BLOCK_SIZE, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+    VERIFY(block != MAP_FAILED);
+#else
+    auto* block = (HeapBlock*)VirtualAlloc(NULL, WeakBlock::BLOCK_SIZE, MEM_COMMIT, PAGE_READWRITE);
+    VERIFY(block);
+#endif
+    return new (block) WeakBlock;
+}
+
+WeakBlock::WeakBlock()
+{
+    for (size_t i = 0; i < IMPL_COUNT; ++i) {
+        m_impls[i].set_ptr({}, i + 1 < IMPL_COUNT ? &m_impls[i + 1] : nullptr);
+        m_impls[i].set_state(WeakImpl::State::Freelist);
+    }
+    m_freelist = &m_impls[0];
+}
+
+WeakBlock::~WeakBlock() = default;
+
+WeakImpl* WeakBlock::allocate(Cell* cell)
+{
+    auto* impl = m_freelist;
+    if (!impl)
+        return nullptr;
+    VERIFY(impl->ref_count() == 0);
+    m_freelist = impl->ptr() ? static_cast<WeakImpl*>(impl->ptr()) : nullptr;
+    impl->set_ptr({}, cell);
+    impl->set_state(WeakImpl::State::Allocated);
+    return impl;
+}
+
+void WeakBlock::deallocate(WeakImpl* impl)
+{
+    VERIFY(impl->ref_count() == 0);
+    impl->set_ptr({}, m_freelist);
+    impl->set_state(WeakImpl::State::Freelist);
+    m_freelist = impl;
+}
+
+void WeakBlock::sweep()
+{
+    for (size_t i = 0; i < IMPL_COUNT; ++i) {
+        auto& impl = m_impls[i];
+        if (impl.state() == WeakImpl::State::Freelist)
+            continue;
+        auto* cell = static_cast<Cell*>(impl.ptr());
+        if (!cell || !cell->is_marked())
+            impl.set_ptr({}, nullptr);
+        if (impl.ref_count() == 0)
+            deallocate(&impl);
+    }
+}
+
+}
diff --git a/Libraries/LibGC/WeakBlock.h b/Libraries/LibGC/WeakBlock.h
new file mode 100644
index 00000000000..c475ddd0e60
--- /dev/null
+++ b/Libraries/LibGC/WeakBlock.h
@@ -0,0 +1,45 @@
+/*
+ * Copyright (c) 2025, Andreas Kling <andreas@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/IntrusiveList.h>
+#include <LibGC/Forward.h>
+#include <LibGC/Weak.h>
+
+namespace GC {
+
+class GC_API WeakBlock {
+public:
+    static constexpr size_t BLOCK_SIZE = 16 * KiB;
+
+    static WeakBlock* create();
+
+    WeakImpl* allocate(Cell*);
+    void deallocate(WeakImpl*);
+
+    bool can_allocate() const { return m_freelist != nullptr; }
+
+    void sweep();
+
+private:
+    WeakBlock();
+    ~WeakBlock();
+
+    IntrusiveListNode<WeakBlock> m_list_node;
+
+public:
+    using List = IntrusiveList<&WeakBlock::m_list_node>;
+
+    WeakImpl* m_freelist { nullptr };
+
+    static constexpr size_t IMPL_COUNT = (BLOCK_SIZE - sizeof(m_list_node) - sizeof(WeakImpl*)) / sizeof(WeakImpl);
+    WeakImpl m_impls[IMPL_COUNT];
+};
+
+static_assert(sizeof(WeakBlock) <= WeakBlock::BLOCK_SIZE);
+
+}
diff --git a/Libraries/LibGC/WeakInlines.h b/Libraries/LibGC/WeakInlines.h
new file mode 100644
index 00000000000..9a8fa00619a
--- /dev/null
+++ b/Libraries/LibGC/WeakInlines.h
@@ -0,0 +1,113 @@
+/*
+ * Copyright (c) 2025, Andreas Kling <andreas@ladybird.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibGC/Weak.h>
+
+namespace GC {
+
+template<typename T>
+Weak<T>::Weak(T const* ptr)
+    : m_impl(ptr ? *ptr->heap().create_weak_impl(const_cast<void*>(static_cast<void const*>(ptr))) : WeakImpl::the_null_weak_impl)
+{
+}
+
+template<typename T>
+Weak<T>::Weak(T const& ptr)
+    : m_impl(*ptr.heap().create_weak_impl(const_cast<void*>(static_cast<void const*>(&ptr))))
+{
+}
+
+template<typename T>
+template<typename U>
+Weak<T>::Weak(Weak<U> const& other)
+requires(IsConvertible<U*, T*>)
+    : m_impl(other.impl())
+{
+}
+
+template<typename T>
+Weak<T>::Weak(Ref<T> const& other)
+    : m_impl(*other.ptr()->heap().create_weak_impl(other.ptr()))
+{
+}
+
+template<typename T>
+template<typename U>
+Weak<T>::Weak(Ref<U> const& other)
+requires(IsConvertible<U*, T*>)
+    : m_impl(*other.ptr()->heap().create_weak_impl(other.ptr()))
+{
+}
+
+template<typename T>
+template<typename U>
+Weak<T>& Weak<T>::operator=(U const& other)
+requires(IsConvertible<U*, T*>)
+{
+    if (ptr() != other) {
+        m_impl = *other.heap().create_weak_impl(const_cast<void*>(static_cast<void const*>(&other)));
+    }
+    return *this;
+}
+
+template<typename T>
+Weak<T>& Weak<T>::operator=(Ref<T> const& other)
+{
+    if (ptr() != other.ptr()) {
+        m_impl = *other.ptr()->heap().create_weak_impl(other.ptr());
+    }
+    return *this;
+}
+
+template<typename T>
+template<typename U>
+Weak<T>& Weak<T>::operator=(Ref<U> const& other)
+requires(IsConvertible<U*, T*>)
+{
+    if (ptr() != other.ptr()) {
+        m_impl = *other.ptr()->heap().create_weak_impl(other.ptr());
+    }
+    return *this;
+}
+
+template<typename T>
+Weak<T>& Weak<T>::operator=(T const& other)
+{
+    if (ptr() != &other) {
+        m_impl = *other.heap().create_weak_impl(const_cast<void*>(static_cast<void const*>(&other)));
+    }
+    return *this;
+}
+
+template<typename T>
+Weak<T>& Weak<T>::operator=(T const* other)
+{
+    if (ptr() != other) {
+        if (other)
+            m_impl = *other->heap().create_weak_impl(const_cast<void*>(static_cast<void const*>(other)));
+        else
+            m_impl = WeakImpl::the_null_weak_impl;
+    }
+    return *this;
+}
+
+template<typename T>
+template<typename U>
+Weak<T>& Weak<T>::operator=(U const* other)
+requires(IsConvertible<U*, T*>)
+{
+    if (ptr() != other) {
+        if (other)
+            m_impl = *other->heap().create_weak_impl(const_cast<void*>(static_cast<void const*>(other)));
+        else
+            m_impl = WeakImpl::the_null_weak_impl;
+    }
+    return *this;
+}
+
+}
diff --git a/Libraries/LibJS/Bytecode/Executable.h b/Libraries/LibJS/Bytecode/Executable.h
index 54e95ee12ab..2dd945fd841 100644
--- a/Libraries/LibJS/Bytecode/Executable.h
+++ b/Libraries/LibJS/Bytecode/Executable.h
@@ -10,8 +10,9 @@
 #include <AK/NonnullOwnPtr.h>
 #include <AK/OwnPtr.h>
 #include <AK/Utf16FlyString.h>
-#include <AK/WeakPtr.h>
 #include <LibGC/CellAllocator.h>
+#include <LibGC/Weak.h>
+#include <LibGC/WeakInlines.h>
 #include <LibJS/Bytecode/IdentifierTable.h>
 #include <LibJS/Bytecode/Label.h>
 #include <LibJS/Bytecode/StringTable.h>
@@ -37,11 +38,11 @@ struct PropertyLookupCache {
             GetPropertyInPrototypeChain,
         };
         Type type { Type::Empty };
-        WeakPtr<Shape> from_shape;
-        WeakPtr<Shape> shape;
+        GC::Weak<Shape> from_shape;
+        GC::Weak<Shape> shape;
         Optional<u32> property_offset;
-        WeakPtr<Object> prototype;
-        WeakPtr<PrototypeChainValidity> prototype_chain_validity;
+        GC::Weak<Object> prototype;
+        GC::Weak<PrototypeChainValidity> prototype_chain_validity;
     };
     AK::Array<Entry, max_number_of_shapes_to_remember> entries;
 };
diff --git a/Libraries/LibJS/Bytecode/Interpreter.cpp b/Libraries/LibJS/Bytecode/Interpreter.cpp
index 92627013ec7..66bc0d8e65e 100644
--- a/Libraries/LibJS/Bytecode/Interpreter.cpp
+++ b/Libraries/LibJS/Bytecode/Interpreter.cpp
@@ -1133,20 +1133,22 @@ ThrowCompletionOr<void> put_by_property_key(VM& vm, Value base, Value this_value
                 case PropertyLookupCache::Entry::Type::Empty:
                     break;
                 case PropertyLookupCache::Entry::Type::ChangePropertyInPrototypeChain: {
-                    if (!cache.prototype) [[unlikely]]
+                    auto cached_prototype = cache.prototype.ptr();
+                    if (!cached_prototype) [[unlikely]]
                         break;
                     // OPTIMIZATION: If the prototype chain hasn't been mutated in a way that would invalidate the cache, we can use it.
                     bool can_use_cache = [&]() -> bool {
                         if (&object->shape() != cache.shape) [[unlikely]]
                             return false;
-                        if (!cache.prototype_chain_validity) [[unlikely]]
+                        auto cached_prototype_chain_validity = cache.prototype_chain_validity.ptr();
+                        if (!cached_prototype_chain_validity) [[unlikely]]
                             return false;
-                        if (!cache.prototype_chain_validity->is_valid()) [[unlikely]]
+                        if (!cached_prototype_chain_validity->is_valid()) [[unlikely]]
                             return false;
                         return true;
                     }();
-                    if (can_use_cache) {
-                        auto value_in_prototype = cache.prototype->get_direct(cache.property_offset.value());
+                    if (can_use_cache) [[likely]] {
+                        auto value_in_prototype = cached_prototype->get_direct(cache.property_offset.value());
                         if (value_in_prototype.is_accessor()) [[unlikely]] {
                             (void)TRY(call(vm, value_in_prototype.as_accessor().setter(), this_value, value));
                             return {};
@@ -1170,12 +1172,14 @@ ThrowCompletionOr<void> put_by_property_key(VM& vm, Value base, Value this_value
                     //               reuse the resulting shape from the cache.
                     if (cache.from_shape != &object->shape()) [[unlikely]]
                         break;
-                    if (!cache.shape) [[unlikely]]
+                    auto cached_shape = cache.shape.ptr();
+                    if (!cached_shape) [[unlikely]]
                         break;
                     // The cache is invalid if the prototype chain has been mutated, since such a mutation could have added a setter for the property.
-                    if (cache.prototype_chain_validity && !cache.prototype_chain_validity->is_valid()) [[unlikely]]
+                    auto cached_prototype_chain_validity = cache.prototype_chain_validity.ptr();
+                    if (cached_prototype_chain_validity && !cached_prototype_chain_validity->is_valid()) [[unlikely]]
                         break;
-                    object->unsafe_set_shape(*cache.shape);
+                    object->unsafe_set_shape(*cached_shape);
                     object->put_direct(*cache.property_offset, value);
                     return {};
                 }
diff --git a/Libraries/LibJS/Bytecode/PropertyAccess.h b/Libraries/LibJS/Bytecode/PropertyAccess.h
index a5c9759fe5d..1fb09a0c516 100644
--- a/Libraries/LibJS/Bytecode/PropertyAccess.h
+++ b/Libraries/LibJS/Bytecode/PropertyAccess.h
@@ -92,19 +92,21 @@ ALWAYS_INLINE ThrowCompletionOr<Value> get_by_id(VM& vm, GetBaseIdentifier get_b
         prototype_chain_validity = shape.prototype()->shape().prototype_chain_validity();
 
     for (auto& cache_entry : cache.entries) {
-        if (cache_entry.prototype) {
+        auto cached_prototype = cache_entry.prototype.ptr();
+        if (cached_prototype) {
             // OPTIMIZATION: If the prototype chain hasn't been mutated in a way that would invalidate the cache, we can use it.
             bool can_use_cache = [&]() -> bool {
                 if (&shape != cache_entry.shape) [[unlikely]]
                     return false;
-                if (!cache_entry.prototype_chain_validity) [[unlikely]]
+                auto cached_prototype_chain_validity = cache_entry.prototype_chain_validity.ptr();
+                if (!cached_prototype_chain_validity) [[unlikely]]
                     return false;
-                if (!cache_entry.prototype_chain_validity->is_valid()) [[unlikely]]
+                if (!cached_prototype_chain_validity->is_valid()) [[unlikely]]
                     return false;
                 return true;
             }();
             if (can_use_cache) [[likely]] {
-                auto value = cache_entry.prototype->get_direct(cache_entry.property_offset.value());
+                auto value = cached_prototype->get_direct(cache_entry.property_offset.value());
                 if (value.is_accessor())
                     return TRY(call(vm, value.as_accessor().getter(), this_value));
                 return value;
diff --git a/Libraries/LibJS/Runtime/ExecutionContext.h b/Libraries/LibJS/Runtime/ExecutionContext.h
index cb10fbcde97..58d65f59dbe 100644
--- a/Libraries/LibJS/Runtime/ExecutionContext.h
+++ b/Libraries/LibJS/Runtime/ExecutionContext.h
@@ -9,7 +9,6 @@
 
 #pragma once
 
-#include <AK/WeakPtr.h>
 #include <LibJS/Bytecode/BasicBlock.h>
 #include <LibJS/Export.h>
 #include <LibJS/Forward.h>
diff --git a/Libraries/LibJS/Runtime/Object.h b/Libraries/LibJS/Runtime/Object.h
index 020ba1e15b4..3de452294b0 100644
--- a/Libraries/LibJS/Runtime/Object.h
+++ b/Libraries/LibJS/Runtime/Object.h
@@ -64,8 +64,7 @@ struct CacheableSetPropertyMetadata {
     GC::Ptr<Object const> prototype;
 };
 
-class JS_API Object : public Cell
-    , public Weakable<Object> {
+class JS_API Object : public Cell {
     GC_CELL(Object, Cell);
     GC_DECLARE_ALLOCATOR(Object);
 
diff --git a/Libraries/LibJS/Runtime/Shape.cpp b/Libraries/LibJS/Runtime/Shape.cpp
index ab6327441d9..81a19129a73 100644
--- a/Libraries/LibJS/Runtime/Shape.cpp
+++ b/Libraries/LibJS/Runtime/Shape.cpp
@@ -110,8 +110,8 @@ GC::Ref<Shape> Shape::create_put_transition(PropertyKey const& property_key, Pro
     invalidate_prototype_if_needed_for_new_prototype(new_shape);
     if (!m_is_prototype_shape) {
         if (!m_forward_transitions)
-            m_forward_transitions = make<HashMap<TransitionKey, WeakPtr<Shape>>>();
-        m_forward_transitions->set(key, new_shape.ptr());
+            m_forward_transitions = make<HashMap<TransitionKey, GC::Weak<Shape>>>();
+        m_forward_transitions->set(key, new_shape);
     }
     return new_shape;
 }
@@ -125,7 +125,7 @@ GC::Ref<Shape> Shape::create_configure_transition(PropertyKey const& property_ke
     invalidate_prototype_if_needed_for_new_prototype(new_shape);
     if (!m_is_prototype_shape) {
         if (!m_forward_transitions)
-            m_forward_transitions = make<HashMap<TransitionKey, WeakPtr<Shape>>>();
+            m_forward_transitions = make<HashMap<TransitionKey, GC::Weak<Shape>>>();
         m_forward_transitions->set(key, new_shape.ptr());
     }
     return new_shape;
@@ -141,7 +141,7 @@ GC::Ref<Shape> Shape::create_prototype_transition(Object* new_prototype)
     invalidate_prototype_if_needed_for_new_prototype(new_shape);
     if (!m_is_prototype_shape) {
         if (!m_prototype_transitions)
-            m_prototype_transitions = make<HashMap<GC::Ptr<Object>, WeakPtr<Shape>>>();
+            m_prototype_transitions = make<HashMap<GC::Ptr<Object>, GC::Weak<Shape>>>();
         m_prototype_transitions->set(new_prototype, new_shape.ptr());
     }
     return new_shape;
@@ -279,7 +279,7 @@ GC::Ref<Shape> Shape::create_delete_transition(PropertyKey const& property_key)
     auto new_shape = heap().allocate<Shape>(*this, property_key, TransitionType::Delete);
     invalidate_prototype_if_needed_for_new_prototype(new_shape);
     if (!m_delete_transitions)
-        m_delete_transitions = make<HashMap<PropertyKey, WeakPtr<Shape>>>();
+        m_delete_transitions = make<HashMap<PropertyKey, GC::Weak<Shape>>>();
     m_delete_transitions->set(property_key, new_shape.ptr());
     return new_shape;
 }
diff --git a/Libraries/LibJS/Runtime/Shape.h b/Libraries/LibJS/Runtime/Shape.h
index 454909ebdac..c3fcc4bec8b 100644
--- a/Libraries/LibJS/Runtime/Shape.h
+++ b/Libraries/LibJS/Runtime/Shape.h
@@ -10,8 +10,8 @@
 #include <AK/HashMap.h>
 #include <AK/OwnPtr.h>
 #include <AK/StringView.h>
-#include <AK/WeakPtr.h>
 #include <AK/Weakable.h>
+#include <LibGC/Weak.h>
 #include <LibJS/Export.h>
 #include <LibJS/Forward.h>
 #include <LibJS/Heap/Cell.h>
@@ -36,8 +36,7 @@ struct TransitionKey {
     }
 };
 
-class PrototypeChainValidity final : public Cell
-    , public Weakable<PrototypeChainValidity> {
+class PrototypeChainValidity final : public Cell {
     GC_CELL(PrototypeChainValidity, Cell);
     GC_DECLARE_ALLOCATOR(PrototypeChainValidity);
 
@@ -50,8 +49,7 @@ private:
     size_t padding { 0 };
 };
 
-class JS_API Shape final : public Cell
-    , public Weakable<Shape> {
+class JS_API Shape final : public Cell {
     GC_CELL(Shape, Cell);
     GC_DECLARE_ALLOCATOR(Shape);
 
@@ -129,9 +127,9 @@ private:
 
     mutable OwnPtr<OrderedHashMap<PropertyKey, PropertyMetadata>> m_property_table;
 
-    OwnPtr<HashMap<TransitionKey, WeakPtr<Shape>>> m_forward_transitions;
-    OwnPtr<HashMap<GC::Ptr<Object>, WeakPtr<Shape>>> m_prototype_transitions;
-    OwnPtr<HashMap<PropertyKey, WeakPtr<Shape>>> m_delete_transitions;
+    OwnPtr<HashMap<TransitionKey, GC::Weak<Shape>>> m_forward_transitions;
+    OwnPtr<HashMap<GC::Ptr<Object>, GC::Weak<Shape>>> m_prototype_transitions;
+    OwnPtr<HashMap<PropertyKey, GC::Weak<Shape>>> m_delete_transitions;
     GC::Ptr<Shape> m_previous;
     Optional<PropertyKey> m_property_key;
     GC::Ptr<Object> m_prototype;
diff --git a/Libraries/LibWeb/ARIA/ARIAMixin.cpp b/Libraries/LibWeb/ARIA/ARIAMixin.cpp
index db0559f40c4..180a637c1d9 100644
--- a/Libraries/LibWeb/ARIA/ARIAMixin.cpp
+++ b/Libraries/LibWeb/ARIA/ARIAMixin.cpp
@@ -247,25 +247,25 @@ Vector<String> ARIAMixin::parse_id_reference_list(Optional<String> const& id_lis
 ENUMERATE_ARIA_ELEMENT_REFERENCING_ATTRIBUTES
 #undef __ENUMERATE_ARIA_ATTRIBUTE
 
-#define __ENUMERATE_ARIA_ATTRIBUTE(attribute, referencing_attribute)               \
-    Optional<Vector<WeakPtr<DOM::Element>>> const& ARIAMixin::attribute() const    \
-    {                                                                              \
-        return m_##attribute;                                                      \
-    }                                                                              \
-                                                                                   \
-    void ARIAMixin::set_##attribute(Optional<Vector<WeakPtr<DOM::Element>>> value) \
-    {                                                                              \
-        m_##attribute = move(value);                                               \
-    }                                                                              \
-                                                                                   \
-    GC::Ptr<JS::Array> ARIAMixin::cached_##attribute() const                       \
-    {                                                                              \
-        return m_cached_##attribute;                                               \
-    }                                                                              \
-                                                                                   \
-    void ARIAMixin::set_cached_##attribute(GC::Ptr<JS::Array> value)               \
-    {                                                                              \
-        m_cached_##attribute = value;                                              \
+#define __ENUMERATE_ARIA_ATTRIBUTE(attribute, referencing_attribute)                \
+    Optional<Vector<GC::Weak<DOM::Element>>> const& ARIAMixin::attribute() const    \
+    {                                                                               \
+        return m_##attribute;                                                       \
+    }                                                                               \
+                                                                                    \
+    void ARIAMixin::set_##attribute(Optional<Vector<GC::Weak<DOM::Element>>> value) \
+    {                                                                               \
+        m_##attribute = move(value);                                                \
+    }                                                                               \
+                                                                                    \
+    GC::Ptr<JS::Array> ARIAMixin::cached_##attribute() const                        \
+    {                                                                               \
+        return m_cached_##attribute;                                                \
+    }                                                                               \
+                                                                                    \
+    void ARIAMixin::set_cached_##attribute(GC::Ptr<JS::Array> value)                \
+    {                                                                               \
+        m_cached_##attribute = value;                                               \
     }
 ENUMERATE_ARIA_ELEMENT_LIST_REFERENCING_ATTRIBUTES
 #undef __ENUMERATE_ARIA_ATTRIBUTE
diff --git a/Libraries/LibWeb/ARIA/ARIAMixin.h b/Libraries/LibWeb/ARIA/ARIAMixin.h
index de3943dbacd..13be0d2858f 100644
--- a/Libraries/LibWeb/ARIA/ARIAMixin.h
+++ b/Libraries/LibWeb/ARIA/ARIAMixin.h
@@ -67,11 +67,11 @@ public:
     ENUMERATE_ARIA_ELEMENT_REFERENCING_ATTRIBUTES
 #undef __ENUMERATE_ARIA_ATTRIBUTE
 
-#define __ENUMERATE_ARIA_ATTRIBUTE(attribute, referencing_attribute)  \
-    Optional<Vector<WeakPtr<DOM::Element>>> const& attribute() const; \
-    void set_##attribute(Optional<Vector<WeakPtr<DOM::Element>>>);    \
-                                                                      \
-    GC::Ptr<JS::Array> cached_##attribute() const;                    \
+#define __ENUMERATE_ARIA_ATTRIBUTE(attribute, referencing_attribute)   \
+    Optional<Vector<GC::Weak<DOM::Element>>> const& attribute() const; \
+    void set_##attribute(Optional<Vector<GC::Weak<DOM::Element>>>);    \
+                                                                       \
+    GC::Ptr<JS::Array> cached_##attribute() const;                     \
     void set_cached_##attribute(GC::Ptr<JS::Array>);
     ENUMERATE_ARIA_ELEMENT_LIST_REFERENCING_ATTRIBUTES
 #undef __ENUMERATE_ARIA_ATTRIBUTE
@@ -85,12 +85,12 @@ protected:
 
 private:
 #define __ENUMERATE_ARIA_ATTRIBUTE(attribute, referencing_attribute) \
-    WeakPtr<DOM::Element> m_##attribute;
+    GC::Weak<DOM::Element> m_##attribute;
     ENUMERATE_ARIA_ELEMENT_REFERENCING_ATTRIBUTES
 #undef __ENUMERATE_ARIA_ATTRIBUTE
 
 #define __ENUMERATE_ARIA_ATTRIBUTE(attribute, referencing_attribute) \
-    Optional<Vector<WeakPtr<DOM::Element>>> m_##attribute;           \
+    Optional<Vector<GC::Weak<DOM::Element>>> m_##attribute;          \
     GC::Ptr<JS::Array> m_cached_##attribute;
     ENUMERATE_ARIA_ELEMENT_LIST_REFERENCING_ATTRIBUTES
 #undef __ENUMERATE_ARIA_ATTRIBUTE
diff --git a/Libraries/LibWeb/Bindings/MainThreadVM.cpp b/Libraries/LibWeb/Bindings/MainThreadVM.cpp
index 788d9b7aa2e..7409df4ab17 100644
--- a/Libraries/LibWeb/Bindings/MainThreadVM.cpp
+++ b/Libraries/LibWeb/Bindings/MainThreadVM.cpp
@@ -744,7 +744,7 @@ void queue_mutation_observer_microtask(DOM::Document const& document)
             // 3. For each node of mo’s node list, remove all transient registered observers whose observer is mo from node’s registered observer list.
             for (auto& node : mutation_observer->node_list()) {
                 // FIXME: Is this correct?
-                if (node.is_null())
+                if (!node)
                     continue;
 
                 if (node->registered_observer_list()) {
diff --git a/Libraries/LibWeb/CSS/Fetch.cpp b/Libraries/LibWeb/CSS/Fetch.cpp
index 655c3e9343b..175ae67ffb9 100644
--- a/Libraries/LibWeb/CSS/Fetch.cpp
+++ b/Libraries/LibWeb/CSS/Fetch.cpp
@@ -126,7 +126,7 @@ GC::Ptr<HTML::SharedResourceRequest> fetch_an_external_image_for_a_stylesheet(St
 
     auto shared_resource_request = HTML::SharedResourceRequest::get_or_create(realm, document->page(), request->url());
     shared_resource_request->add_callbacks(
-        [document, weak_document = document->make_weak_ptr<DOM::Document>()] {
+        [document, weak_document = GC::Weak { document }] {
             if (!weak_document)
                 return;
 
diff --git a/Libraries/LibWeb/CSS/MediaQuery.cpp b/Libraries/LibWeb/CSS/MediaQuery.cpp
index 38777478bcc..588207e4094 100644
--- a/Libraries/LibWeb/CSS/MediaQuery.cpp
+++ b/Libraries/LibWeb/CSS/MediaQuery.cpp
@@ -99,7 +99,12 @@ String MediaFeature::to_string() const
 MatchResult MediaFeature::evaluate(DOM::Document const* document) const
 {
     VERIFY(document);
-    VERIFY(document->window());
+
+    // FIXME: In some cases (e.g. when parsing HTML using DOMParser::parse_from_string()) a document may not be associated with a window -
+    //        for now we just return false but perhaps there are some media queries we should still attempt to resolve.
+    if (!document->window())
+        return MatchResult::False;
+
     auto maybe_queried_value = document->window()->query_media_feature(m_id);
     if (!maybe_queried_value.has_value())
         return MatchResult::False;
diff --git a/Libraries/LibWeb/CSS/StyleValues/ImageStyleValue.h b/Libraries/LibWeb/CSS/StyleValues/ImageStyleValue.h
index 4b356b0e887..cc1939f40a2 100644
--- a/Libraries/LibWeb/CSS/StyleValues/ImageStyleValue.h
+++ b/Libraries/LibWeb/CSS/StyleValues/ImageStyleValue.h
@@ -9,6 +9,7 @@
 
 #pragma once
 
+#include <LibGC/Weak.h>
 #include <LibJS/Heap/Cell.h>
 #include <LibWeb/CSS/Enums.h>
 #include <LibWeb/CSS/StyleValues/AbstractImageStyleValue.h>
@@ -79,7 +80,7 @@ private:
     GC::Ptr<CSSStyleSheet> m_style_sheet;
 
     URL m_url;
-    WeakPtr<DOM::Document> m_document;
+    GC::Weak<DOM::Document> m_document;
 
     size_t m_current_frame_index { 0 };
     size_t m_loops_completed { 0 };
diff --git a/Libraries/LibWeb/DOM/Document.cpp b/Libraries/LibWeb/DOM/Document.cpp
index 3b081ec092c..376577dec54 100644
--- a/Libraries/LibWeb/DOM/Document.cpp
+++ b/Libraries/LibWeb/DOM/Document.cpp
@@ -494,8 +494,11 @@ Document::Document(JS::Realm& realm, URL::URL const& url, TemporaryDocumentForFr
     HTML::main_thread_event_loop().register_document({}, *this);
 }
 
-Document::~Document()
+Document::~Document() = default;
+
+void Document::finalize()
 {
+    Base::finalize();
     HTML::main_thread_event_loop().unregister_document({}, *this);
 }
 
@@ -1785,9 +1788,9 @@ void Document::invalidate_style_of_elements_affected_by_has()
 
     auto nodes = move(m_pending_nodes_for_style_invalidation_due_to_presence_of_has);
     for (auto const& node : nodes) {
-        if (node.is_null())
+        if (!node)
             continue;
-        for (auto* ancestor = node.ptr(); ancestor; ancestor = ancestor->parent_or_shadow_host()) {
+        for (auto ancestor = node.ptr(); ancestor; ancestor = ancestor->parent_or_shadow_host()) {
             if (!ancestor->is_element())
                 continue;
             auto& element = static_cast<Element&>(*ancestor);
@@ -3417,7 +3420,7 @@ void Document::run_the_scroll_steps()
 void Document::add_media_query_list(GC::Ref<CSS::MediaQueryList> media_query_list)
 {
     m_needs_media_query_evaluation = true;
-    m_media_query_lists.append(*media_query_list);
+    m_media_query_lists.append(media_query_list);
 }
 
 // https://drafts.csswg.org/cssom-view/#evaluate-media-queries-and-report-changes
@@ -3429,7 +3432,7 @@ void Document::evaluate_media_queries_and_report_changes()
 
     // NOTE: Not in the spec, but we take this opportunity to prune null WeakPtrs.
     m_media_query_lists.remove_all_matching([](auto& it) {
-        return it.is_null();
+        return !it;
     });
 
     // 1. For each MediaQueryList object target that has doc as its document,
@@ -3440,7 +3443,7 @@ void Document::evaluate_media_queries_and_report_changes()
         //    with its type attribute initialized to change, its isTrusted attribute
         //    initialized to true, its media attribute initialized to target’s media,
         //    and its matches attribute initialized to target’s matches state.
-        if (media_query_list_ptr.is_null())
+        if (!media_query_list_ptr)
             continue;
         GC::Ptr<CSS::MediaQueryList> media_query_list = media_query_list_ptr.ptr();
         bool did_match = media_query_list->matches();
@@ -6842,7 +6845,7 @@ NonnullRefPtr<CSS::StyleValue const> Document::custom_property_initial_value(Fly
 GC::Ptr<Element> ElementByIdMap::get(FlyString const& element_id) const
 {
     if (auto elements = m_map.get(element_id); elements.has_value() && !elements->is_empty()) {
-        if (auto element = elements->first(); element.has_value())
+        if (auto element = elements->first())
             return *element;
     }
     return {};
diff --git a/Libraries/LibWeb/DOM/Document.h b/Libraries/LibWeb/DOM/Document.h
index 5e19597a9e2..8a1e5eee81a 100644
--- a/Libraries/LibWeb/DOM/Document.h
+++ b/Libraries/LibWeb/DOM/Document.h
@@ -681,7 +681,7 @@ public:
     WebIDL::ExceptionOr<String> query_command_value(FlyString const& command);
 
     WebIDL::ExceptionOr<GC::Ref<XPath::XPathExpression>> create_expression(String const& expression, GC::Ptr<XPath::XPathNSResolver> resolver = nullptr);
-    WebIDL::ExceptionOr<GC::Ref<XPath::XPathResult>> evaluate(String const& expression, const DOM::Node& context_node, GC::Ptr<XPath::XPathNSResolver> resolver = nullptr, WebIDL::UnsignedShort type = 0, GC::Ptr<XPath::XPathResult> result = nullptr);
+    WebIDL::ExceptionOr<GC::Ref<XPath::XPathResult>> evaluate(String const& expression, DOM::Node const& context_node, GC::Ptr<XPath::XPathNSResolver> resolver = nullptr, WebIDL::UnsignedShort type = 0, GC::Ptr<XPath::XPathResult> result = nullptr);
     GC::Ref<DOM::Node> create_ns_resolver(GC::Ref<DOM::Node> node_resolver); // legacy
 
     // https://w3c.github.io/selection-api/#dfn-has-scheduled-selectionchange-event
@@ -924,7 +924,7 @@ public:
 
     void schedule_ancestors_style_invalidation_due_to_presence_of_has(Node& node)
     {
-        m_pending_nodes_for_style_invalidation_due_to_presence_of_has.set(node.make_weak_ptr<Node>());
+        m_pending_nodes_for_style_invalidation_due_to_presence_of_has.set(node);
     }
 
     ElementByIdMap& element_by_id() const;
@@ -953,6 +953,8 @@ private:
     // ^HTML::GlobalEventHandlers
     virtual GC::Ptr<EventTarget> global_event_handlers_to_event_target(FlyString const&) final { return *this; }
 
+    virtual void finalize() override final;
+
     void invalidate_style_of_elements_affected_by_has();
 
     void tear_down_layout_tree();
@@ -1115,7 +1117,7 @@ private:
 
     // Used by evaluate_media_queries_and_report_changes().
     bool m_needs_media_query_evaluation { false };
-    Vector<WeakPtr<CSS::MediaQueryList>> m_media_query_lists;
+    Vector<GC::Weak<CSS::MediaQueryList>> m_media_query_lists;
 
     bool m_needs_full_style_update { false };
     bool m_needs_full_layout_tree_update { false };
@@ -1278,8 +1280,8 @@ private:
     RefPtr<Core::Timer> m_cursor_blink_timer;
     bool m_cursor_blink_state { false };
 
-    // NOTE: This is WeakPtr, not GCPtr, on purpose. We don't want the document to keep some old detached navigable alive.
-    WeakPtr<HTML::Navigable> m_cached_navigable;
+    // NOTE: This is GC::Weak, not GC::Ptr, on purpose. We don't want the document to keep some old detached navigable alive.
+    GC::Weak<HTML::Navigable> m_cached_navigable;
 
     bool m_enable_cookies_on_file_domains { false };
 
@@ -1331,7 +1333,7 @@ private:
     // https://drafts.csswg.org/css-view-transitions-1/#document-update-callback-queue
     Vector<GC::Ptr<ViewTransition::ViewTransition>> m_update_callback_queue = {};
 
-    HashTable<WeakPtr<Node>> m_pending_nodes_for_style_invalidation_due_to_presence_of_has;
+    HashTable<GC::Weak<Node>> m_pending_nodes_for_style_invalidation_due_to_presence_of_has;
 
     GC::Ref<StyleInvalidator> m_style_invalidator;
 
diff --git a/Libraries/LibWeb/DOM/Element.cpp b/Libraries/LibWeb/DOM/Element.cpp
index 27203e07c8d..e9503cacd57 100644
--- a/Libraries/LibWeb/DOM/Element.cpp
+++ b/Libraries/LibWeb/DOM/Element.cpp
@@ -541,7 +541,7 @@ GC::Ptr<DOM::Element> Element::get_the_attribute_associated_element(FlyString co
 }
 
 // https://html.spec.whatwg.org/multipage/common-dom-interfaces.html#attr-associated-elements
-Optional<GC::RootVector<GC::Ref<DOM::Element>>> Element::get_the_attribute_associated_elements(FlyString const& content_attribute, Optional<Vector<WeakPtr<DOM::Element>>> const& explicitly_set_attribute_elements) const
+Optional<GC::RootVector<GC::Ref<DOM::Element>>> Element::get_the_attribute_associated_elements(FlyString const& content_attribute, Optional<Vector<GC::Weak<DOM::Element>>> const& explicitly_set_attribute_elements) const
 {
     // 1. Let elements be an empty list.
     GC::RootVector<GC::Ref<DOM::Element>> elements(heap());
diff --git a/Libraries/LibWeb/DOM/Element.h b/Libraries/LibWeb/DOM/Element.h
index a8bf89a8152..2fd9b30f3bf 100644
--- a/Libraries/LibWeb/DOM/Element.h
+++ b/Libraries/LibWeb/DOM/Element.h
@@ -173,7 +173,7 @@ public:
     GC::Ptr<Attr> get_attribute_node_ns(Optional<FlyString> const& namespace_, FlyString const& name) const;
 
     GC::Ptr<DOM::Element> get_the_attribute_associated_element(FlyString const& content_attribute, GC::Ptr<DOM::Element> explicitly_set_attribute_element) const;
-    Optional<GC::RootVector<GC::Ref<DOM::Element>>> get_the_attribute_associated_elements(FlyString const& content_attribute, Optional<Vector<WeakPtr<DOM::Element>>> const& explicitly_set_attribute_elements) const;
+    Optional<GC::RootVector<GC::Ref<DOM::Element>>> get_the_attribute_associated_elements(FlyString const& content_attribute, Optional<Vector<GC::Weak<DOM::Element>>> const& explicitly_set_attribute_elements) const;
 
     DOMTokenList* class_list();
 
diff --git a/Libraries/LibWeb/DOM/ElementByIdMap.cpp b/Libraries/LibWeb/DOM/ElementByIdMap.cpp
index 229984ba40e..c7d8e415ee5 100644
--- a/Libraries/LibWeb/DOM/ElementByIdMap.cpp
+++ b/Libraries/LibWeb/DOM/ElementByIdMap.cpp
@@ -10,17 +10,17 @@ namespace Web::DOM {
 
 void ElementByIdMap::add(FlyString const& element_id, Element& element)
 {
-    auto& elements_with_id = m_map.ensure(element_id, [] { return Vector<WeakPtr<Element>> {}; });
+    auto& elements_with_id = m_map.ensure(element_id, [] { return Vector<GC::Weak<Element>> {}; });
 
     // Remove all elements that were deallocated.
-    elements_with_id.remove_all_matching([](WeakPtr<Element>& element) {
-        return !element.has_value();
+    elements_with_id.remove_all_matching([](GC::Weak<Element>& element) {
+        return !element;
     });
 
     elements_with_id.remove_first_matching([&](auto const& another_element) {
         return &element == another_element.ptr();
     });
-    elements_with_id.insert_before_matching(element, [&](auto& another_element) {
+    elements_with_id.insert_before_matching(GC::Weak<Element> { element }, [&](auto& another_element) {
         return element.is_before(*another_element);
     });
 }
@@ -32,7 +32,7 @@ void ElementByIdMap::remove(FlyString const& element_id, Element& element)
         return;
     auto& elements_with_id = *maybe_elements_with_id;
     elements_with_id.remove_all_matching([&](auto& another_element) {
-        if (!another_element.has_value())
+        if (!another_element)
             return true;
         return &element == another_element.ptr();
     });
diff --git a/Libraries/LibWeb/DOM/ElementByIdMap.h b/Libraries/LibWeb/DOM/ElementByIdMap.h
index 57b12678342..cfb528ec6a2 100644
--- a/Libraries/LibWeb/DOM/ElementByIdMap.h
+++ b/Libraries/LibWeb/DOM/ElementByIdMap.h
@@ -18,7 +18,7 @@ public:
     GC::Ptr<Element> get(FlyString const& element_id) const;
 
 private:
-    HashMap<FlyString, Vector<WeakPtr<Element>>> m_map;
+    HashMap<FlyString, Vector<GC::Weak<Element>>> m_map;
 };
 
 }
diff --git a/Libraries/LibWeb/DOM/MutationObserver.cpp b/Libraries/LibWeb/DOM/MutationObserver.cpp
index 5f30c900953..ea6a847e396 100644
--- a/Libraries/LibWeb/DOM/MutationObserver.cpp
+++ b/Libraries/LibWeb/DOM/MutationObserver.cpp
@@ -97,7 +97,7 @@ WebIDL::ExceptionOr<void> MutationObserver::observe(Node& target, MutationObserv
             // 1. For each node of this’s node list, remove all transient registered observers whose source is registered from node’s registered observer list.
             for (auto& node : m_node_list) {
                 // FIXME: Is this correct?
-                if (node.is_null())
+                if (!node)
                     continue;
 
                 if (node->registered_observer_list()) {
@@ -120,7 +120,7 @@ WebIDL::ExceptionOr<void> MutationObserver::observe(Node& target, MutationObserv
         target.add_registered_observer(new_registered_observer);
 
         // 2. Append target to this’s node list.
-        m_node_list.append(target.make_weak_ptr<Node>());
+        m_node_list.append(target);
     }
 
     return {};
@@ -132,7 +132,7 @@ void MutationObserver::disconnect()
     // 1. For each node of this’s node list, remove any registered observer from node’s registered observer list for which this is the observer.
     for (auto& node : m_node_list) {
         // FIXME: Is this correct?
-        if (node.is_null())
+        if (!node)
             continue;
 
         if (node->registered_observer_list()) {
diff --git a/Libraries/LibWeb/DOM/MutationObserver.h b/Libraries/LibWeb/DOM/MutationObserver.h
index 2b334b23e93..e9c3483f9c0 100644
--- a/Libraries/LibWeb/DOM/MutationObserver.h
+++ b/Libraries/LibWeb/DOM/MutationObserver.h
@@ -38,8 +38,8 @@ public:
     void disconnect();
     Vector<GC::Root<MutationRecord>> take_records();
 
-    Vector<WeakPtr<Node>>& node_list() { return m_node_list; }
-    Vector<WeakPtr<Node>> const& node_list() const { return m_node_list; }
+    Vector<GC::Weak<Node>>& node_list() { return m_node_list; }
+    Vector<GC::Weak<Node>> const& node_list() const { return m_node_list; }
 
     WebIDL::CallbackType& callback() { return *m_callback; }
 
@@ -61,7 +61,7 @@ private:
     // https://dom.spec.whatwg.org/#mutationobserver-node-list
     // NOTE: These are weak, per https://dom.spec.whatwg.org/#garbage-collection
     // Registered observers in a node’s registered observer list have a weak reference to the node.
-    Vector<WeakPtr<Node>> m_node_list;
+    Vector<GC::Weak<Node>> m_node_list;
 
     // https://dom.spec.whatwg.org/#concept-mo-queue
     Vector<GC::Ref<MutationRecord>> m_record_queue;
diff --git a/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp b/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
index 857a673d917..d275eb2c414 100644
--- a/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
+++ b/Libraries/LibWeb/HTML/CanvasRenderingContext2D.cpp
@@ -100,8 +100,13 @@ void CanvasRenderingContext2D::fill_rect(float x, float y, float width, float he
     fill_internal(rect_path(x, y, width, height), Gfx::WindingRule::EvenOdd);
 }
 
+// https://html.spec.whatwg.org/multipage/canvas.html#dom-context-2d-clearrect
 void CanvasRenderingContext2D::clear_rect(float x, float y, float width, float height)
 {
+    // 1. If any of the arguments are infinite or NaN, then return.
+    if (!isfinite(x) || !isfinite(y) || !isfinite(width) || !isfinite(height))
+        return;
+
     if (auto* painter = this->painter()) {
         auto rect = Gfx::FloatRect(x, y, width, height);
         painter->clear_rect(rect, clear_color());
diff --git a/Libraries/LibWeb/HTML/EventLoop/EventLoop.h b/Libraries/LibWeb/HTML/EventLoop/EventLoop.h
index 14df272e813..5d41e7ecda2 100644
--- a/Libraries/LibWeb/HTML/EventLoop/EventLoop.h
+++ b/Libraries/LibWeb/HTML/EventLoop/EventLoop.h
@@ -8,9 +8,9 @@
 
 #include <AK/Function.h>
 #include <AK/Noncopyable.h>
-#include <AK/WeakPtr.h>
 #include <LibCore/Forward.h>
 #include <LibGC/Ptr.h>
+#include <LibGC/Weak.h>
 #include <LibJS/Forward.h>
 #include <LibWeb/Export.h>
 #include <LibWeb/HTML/EventLoop/TaskQueue.h>
@@ -119,7 +119,7 @@ private:
     // https://html.spec.whatwg.org/multipage/webappapis.html#performing-a-microtask-checkpoint
     bool m_performing_a_microtask_checkpoint { false };
 
-    Vector<WeakPtr<DOM::Document>> m_documents;
+    Vector<GC::Weak<DOM::Document>> m_documents;
 
     // Used to implement step 4 of "perform a microtask checkpoint".
     // NOTE: These are weak references! ESO registers and unregisters itself from the event loop manually.
diff --git a/Libraries/LibWeb/HTML/FormAssociatedElement.h b/Libraries/LibWeb/HTML/FormAssociatedElement.h
index 1d61b0c72fe..8fd3235baf3 100644
--- a/Libraries/LibWeb/HTML/FormAssociatedElement.h
+++ b/Libraries/LibWeb/HTML/FormAssociatedElement.h
@@ -8,7 +8,7 @@
 #pragma once
 
 #include <AK/String.h>
-#include <AK/WeakPtr.h>
+#include <LibGC/Weak.h>
 #include <LibWeb/Bindings/HTMLFormElementPrototype.h>
 #include <LibWeb/DOM/InputEventsTarget.h>
 #include <LibWeb/Export.h>
@@ -178,7 +178,7 @@ protected:
 private:
     void reset_form_owner();
 
-    WeakPtr<HTMLFormElement> m_form;
+    GC::Weak<HTMLFormElement> m_form;
 
     // https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#parser-inserted-flag
     bool m_parser_inserted { false };
diff --git a/Libraries/LibWeb/HTML/HTMLInputElement.cpp b/Libraries/LibWeb/HTML/HTMLInputElement.cpp
index 74089fb424e..990aab8c878 100644
--- a/Libraries/LibWeb/HTML/HTMLInputElement.cpp
+++ b/Libraries/LibWeb/HTML/HTMLInputElement.cpp
@@ -380,7 +380,7 @@ static void show_the_picker_if_applicable(HTMLInputElement& element)
             // 2. Wait for the user to have made their selection.
             auto accepted_file_types = element.parse_accept_attribute();
             auto allow_multiple_files = element.has_attribute(HTML::AttributeNames::multiple) ? AllowMultipleFiles::Yes : AllowMultipleFiles::No;
-            auto weak_element = element.make_weak_ptr<HTMLInputElement>();
+            auto weak_element = GC::Weak<HTMLInputElement> { element };
 
             element.set_is_open(true);
             element.document().browsing_context()->top_level_browsing_context()->page().did_request_file_picker(weak_element, accepted_file_types, allow_multiple_files);
@@ -404,7 +404,7 @@ static void show_the_picker_if_applicable(HTMLInputElement& element)
     //    events, or a cancel event.)
     else {
         if (element.type_state() == HTMLInputElement::TypeAttributeState::Color) {
-            auto weak_element = element.make_weak_ptr<HTMLInputElement>();
+            auto weak_element = GC::Weak<HTMLInputElement> { element };
             element.set_is_open(true);
             element.document().browsing_context()->top_level_browsing_context()->page().did_request_color_picker(weak_element, Color::from_utf16_string(element.value()).value_or(Color(0, 0, 0)));
         }
diff --git a/Libraries/LibWeb/HTML/HTMLLinkElement.cpp b/Libraries/LibWeb/HTML/HTMLLinkElement.cpp
index 0905ef6cfdd..84648c497b3 100644
--- a/Libraries/LibWeb/HTML/HTMLLinkElement.cpp
+++ b/Libraries/LibWeb/HTML/HTMLLinkElement.cpp
@@ -570,7 +570,7 @@ bool HTMLLinkElement::stylesheet_linked_resource_fetch_setup_steps(Fetch::Infras
 
 void HTMLLinkElement::set_parser_document(Badge<HTMLParser>, GC::Ref<DOM::Document> document)
 {
-    m_parser_document = document->make_weak_ptr<DOM::Document>();
+    m_parser_document = document;
 }
 
 bool HTMLLinkElement::is_implicitly_potentially_render_blocking() const
diff --git a/Libraries/LibWeb/HTML/HTMLLinkElement.h b/Libraries/LibWeb/HTML/HTMLLinkElement.h
index 7d4813d950a..629f4c1ab77 100644
--- a/Libraries/LibWeb/HTML/HTMLLinkElement.h
+++ b/Libraries/LibWeb/HTML/HTMLLinkElement.h
@@ -167,7 +167,7 @@ private:
 
     Optional<String> m_mime_type;
 
-    WeakPtr<DOM::Document> m_parser_document;
+    GC::Weak<DOM::Document> m_parser_document;
 };
 
 }
diff --git a/Libraries/LibWeb/HTML/HTMLSelectElement.cpp b/Libraries/LibWeb/HTML/HTMLSelectElement.cpp
index fdb1a8e81b4..eb53e22d199 100644
--- a/Libraries/LibWeb/HTML/HTMLSelectElement.cpp
+++ b/Libraries/LibWeb/HTML/HTMLSelectElement.cpp
@@ -480,7 +480,7 @@ void HTMLSelectElement::show_the_picker_if_applicable()
     }
 
     // Request select dropdown
-    auto weak_element = make_weak_ptr<HTMLSelectElement>();
+    auto weak_element = GC::Weak<HTMLSelectElement> { *this };
     auto rect = get_bounding_client_rect();
     auto position = document().navigable()->to_top_level_position(Web::CSSPixelPoint { rect.x(), rect.bottom() });
     document().page().did_request_select_dropdown(weak_element, position, rect.width(), m_select_items);
diff --git a/Libraries/LibWeb/HTML/HTMLTextAreaElement.cpp b/Libraries/LibWeb/HTML/HTMLTextAreaElement.cpp
index 85639cde151..dda2ba70a1b 100644
--- a/Libraries/LibWeb/HTML/HTMLTextAreaElement.cpp
+++ b/Libraries/LibWeb/HTML/HTMLTextAreaElement.cpp
@@ -31,10 +31,10 @@ GC_DEFINE_ALLOCATOR(HTMLTextAreaElement);
 
 HTMLTextAreaElement::HTMLTextAreaElement(DOM::Document& document, DOM::QualifiedName qualified_name)
     : HTMLElement(document, move(qualified_name))
-    , m_input_event_timer(Core::Timer::create_single_shot(0, [weak_this = make_weak_ptr()]() {
+    , m_input_event_timer(Core::Timer::create_single_shot(0, [weak_this = GC::Weak<HTMLTextAreaElement> { *this }]() {
         if (!weak_this)
             return;
-        static_cast<HTMLTextAreaElement*>(weak_this.ptr())->queue_firing_input_event();
+        weak_this->queue_firing_input_event();
     }))
 {
 }
diff --git a/Libraries/LibWeb/HTML/Navigable.h b/Libraries/LibWeb/HTML/Navigable.h
index de3fa2027bf..9e4f700594d 100644
--- a/Libraries/LibWeb/HTML/Navigable.h
+++ b/Libraries/LibWeb/HTML/Navigable.h
@@ -51,8 +51,7 @@ struct PaintConfig {
 };
 
 // https://html.spec.whatwg.org/multipage/document-sequences.html#navigable
-class WEB_API Navigable : public JS::Cell
-    , public Weakable<Navigable> {
+class WEB_API Navigable : public JS::Cell {
     GC_CELL(Navigable, JS::Cell);
     GC_DECLARE_ALLOCATOR(Navigable);
 
diff --git a/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.cpp b/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.cpp
index f7154f69fb3..241ad3d5fec 100644
--- a/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.cpp
+++ b/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.cpp
@@ -298,7 +298,7 @@ CSSPixelRect IntersectionObserver::root_intersection_rectangle() const
     } else {
         document = &intersection_root.get<GC::Root<DOM::Element>>().cell()->document();
     }
-    if (m_document.has_value() && document->origin().is_same_origin(m_document->origin())) {
+    if (m_document && document->origin().is_same_origin(m_document->origin())) {
         if (auto layout_node = intersection_root.visit([&](auto& node) -> GC::Ptr<Layout::Node> { return node->layout_node(); })) {
             rect.inflate(
                 m_root_margin[0].to_px(*layout_node, rect.height()),
diff --git a/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.h b/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.h
index 1ea66401e6b..9f1489bdea1 100644
--- a/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.h
+++ b/Libraries/LibWeb/IntersectionObserver/IntersectionObserver.h
@@ -106,7 +106,7 @@ private:
     Vector<GC::Ref<DOM::Element>> m_observation_targets;
 
     // AD-HOC: This is the document where we've registered the IntersectionObserver.
-    WeakPtr<DOM::Document> m_document;
+    GC::Weak<DOM::Document> m_document;
 };
 
 }
diff --git a/Libraries/LibWeb/Page/EventHandler.h b/Libraries/LibWeb/Page/EventHandler.h
index 6a47bc175ce..c4d41007520 100644
--- a/Libraries/LibWeb/Page/EventHandler.h
+++ b/Libraries/LibWeb/Page/EventHandler.h
@@ -86,7 +86,7 @@ private:
 
     NonnullOwnPtr<DragAndDropEventHandler> m_drag_and_drop_event_handler;
 
-    WeakPtr<DOM::EventTarget> m_mousedown_target;
+    GC::Weak<DOM::EventTarget> m_mousedown_target;
 
     Optional<CSSPixelPoint> m_mousemove_previous_screen_position;
 
diff --git a/Libraries/LibWeb/Page/Page.cpp b/Libraries/LibWeb/Page/Page.cpp
index 535048a1631..8e56432144e 100644
--- a/Libraries/LibWeb/Page/Page.cpp
+++ b/Libraries/LibWeb/Page/Page.cpp
@@ -68,7 +68,7 @@ void Page::set_focused_navigable(Badge<EventHandler>, HTML::Navigable& navigable
 void Page::navigable_document_destroyed(Badge<DOM::Document>, HTML::Navigable& navigable)
 {
     if (&navigable == m_focused_navigable.ptr())
-        m_focused_navigable.clear();
+        m_focused_navigable = nullptr;
 }
 
 void Page::load(URL::URL const& url)
@@ -405,7 +405,7 @@ void Page::on_pending_dialog_closed()
     }
 }
 
-void Page::did_request_color_picker(WeakPtr<HTML::HTMLInputElement> target, Color current_color)
+void Page::did_request_color_picker(GC::Weak<HTML::HTMLInputElement> target, Color current_color)
 {
     if (m_pending_non_blocking_dialog == PendingNonBlockingDialog::None) {
         m_pending_non_blocking_dialog = PendingNonBlockingDialog::ColorPicker;
@@ -425,12 +425,12 @@ void Page::color_picker_update(Optional<Color> picked_color, HTML::ColorPickerUp
             auto& input_element = as<HTML::HTMLInputElement>(*m_pending_non_blocking_dialog_target);
             input_element.did_pick_color(move(picked_color), state);
             if (state == HTML::ColorPickerUpdateState::Closed)
-                m_pending_non_blocking_dialog_target.clear();
+                m_pending_non_blocking_dialog_target = nullptr;
         }
     }
 }
 
-void Page::did_request_file_picker(WeakPtr<HTML::HTMLInputElement> target, HTML::FileFilter const& accepted_file_types, HTML::AllowMultipleFiles allow_multiple_files)
+void Page::did_request_file_picker(GC::Weak<HTML::HTMLInputElement> target, HTML::FileFilter const& accepted_file_types, HTML::AllowMultipleFiles allow_multiple_files)
 {
     if (m_pending_non_blocking_dialog == PendingNonBlockingDialog::None) {
         m_pending_non_blocking_dialog = PendingNonBlockingDialog::FilePicker;
@@ -449,12 +449,12 @@ void Page::file_picker_closed(Span<HTML::SelectedFile> selected_files)
             auto& input_element = as<HTML::HTMLInputElement>(*m_pending_non_blocking_dialog_target);
             input_element.did_select_files(selected_files);
 
-            m_pending_non_blocking_dialog_target.clear();
+            m_pending_non_blocking_dialog_target = nullptr;
         }
     }
 }
 
-void Page::did_request_select_dropdown(WeakPtr<HTML::HTMLSelectElement> target, Web::CSSPixelPoint content_position, Web::CSSPixels minimum_width, Vector<Web::HTML::SelectItem> items)
+void Page::did_request_select_dropdown(GC::Weak<HTML::HTMLSelectElement> target, Web::CSSPixelPoint content_position, Web::CSSPixels minimum_width, Vector<Web::HTML::SelectItem> items)
 {
     if (m_pending_non_blocking_dialog == PendingNonBlockingDialog::None) {
         m_pending_non_blocking_dialog = PendingNonBlockingDialog::Select;
@@ -471,7 +471,7 @@ void Page::select_dropdown_closed(Optional<u32> const& selected_item_id)
         if (m_pending_non_blocking_dialog_target) {
             auto& select_element = as<HTML::HTMLSelectElement>(*m_pending_non_blocking_dialog_target);
             select_element.did_select_item(selected_item_id);
-            m_pending_non_blocking_dialog_target.clear();
+            m_pending_non_blocking_dialog_target = nullptr;
         }
     }
 }
diff --git a/Libraries/LibWeb/Page/Page.h b/Libraries/LibWeb/Page/Page.h
index bd66fb732c7..ae7140885d6 100644
--- a/Libraries/LibWeb/Page/Page.h
+++ b/Libraries/LibWeb/Page/Page.h
@@ -9,8 +9,8 @@
 
 #pragma once
 
-#include <AK/WeakPtr.h>
 #include <LibGC/Root.h>
+#include <LibGC/Weak.h>
 #include <LibGfx/Cursor.h>
 #include <LibGfx/Forward.h>
 #include <LibGfx/Palette.h>
@@ -159,13 +159,13 @@ public:
     void dismiss_dialog(GC::Ref<GC::Function<void()>> on_dialog_closed);
     void accept_dialog(GC::Ref<GC::Function<void()>> on_dialog_closed);
 
-    void did_request_color_picker(WeakPtr<HTML::HTMLInputElement> target, Color current_color);
+    void did_request_color_picker(GC::Weak<HTML::HTMLInputElement> target, Color current_color);
     void color_picker_update(Optional<Color> picked_color, HTML::ColorPickerUpdateState state);
 
-    void did_request_file_picker(WeakPtr<HTML::HTMLInputElement> target, HTML::FileFilter const& accepted_file_types, HTML::AllowMultipleFiles);
+    void did_request_file_picker(GC::Weak<HTML::HTMLInputElement> target, HTML::FileFilter const& accepted_file_types, HTML::AllowMultipleFiles);
     void file_picker_closed(Span<HTML::SelectedFile> selected_files);
 
-    void did_request_select_dropdown(WeakPtr<HTML::HTMLSelectElement> target, Web::CSSPixelPoint content_position, Web::CSSPixels minimum_width, Vector<Web::HTML::SelectItem> items);
+    void did_request_select_dropdown(GC::Weak<HTML::HTMLSelectElement> target, Web::CSSPixelPoint content_position, Web::CSSPixels minimum_width, Vector<Web::HTML::SelectItem> items);
     void select_dropdown_closed(Optional<u32> const& selected_item_id);
 
     using ClipboardRequest = GC::Ref<GC::Function<void(Vector<Clipboard::SystemClipboardItem>)>>;
@@ -246,7 +246,7 @@ private:
 
     GC::Ref<PageClient> m_client;
 
-    WeakPtr<HTML::Navigable> m_focused_navigable;
+    GC::Weak<HTML::Navigable> m_focused_navigable;
 
     GC::Ptr<HTML::TraversableNavigable> m_top_level_traversable;
 
@@ -275,7 +275,7 @@ private:
     GC::Ptr<GC::Function<void()>> m_on_pending_dialog_closed;
 
     PendingNonBlockingDialog m_pending_non_blocking_dialog { PendingNonBlockingDialog::None };
-    WeakPtr<HTML::HTMLElement> m_pending_non_blocking_dialog_target;
+    GC::Weak<HTML::HTMLElement> m_pending_non_blocking_dialog_target;
 
     HashMap<u64, ClipboardRequest> m_pending_clipboard_requests;
     u64 m_next_clipboard_request_id { 0 };
diff --git a/Libraries/LibWeb/Painting/PaintableBox.h b/Libraries/LibWeb/Painting/PaintableBox.h
index 3f321249d02..bd5199f38a8 100644
--- a/Libraries/LibWeb/Painting/PaintableBox.h
+++ b/Libraries/LibWeb/Painting/PaintableBox.h
@@ -25,8 +25,7 @@ namespace Web::Painting {
 
 WEB_API void set_paint_viewport_scrollbars(bool enabled);
 
-class WEB_API PaintableBox : public Paintable
-    , public Weakable<PaintableBox> {
+class WEB_API PaintableBox : public Paintable {
     GC_CELL(PaintableBox, Paintable);
 
 public:
diff --git a/Libraries/LibWeb/Painting/ScrollFrame.h b/Libraries/LibWeb/Painting/ScrollFrame.h
index c93d42e94a6..a5604cd8da9 100644
--- a/Libraries/LibWeb/Painting/ScrollFrame.h
+++ b/Libraries/LibWeb/Painting/ScrollFrame.h
@@ -6,7 +6,7 @@
 
 #pragma once
 
-#include <AK/WeakPtr.h>
+#include <LibGC/Weak.h>
 #include <LibWeb/Forward.h>
 #include <LibWeb/PixelUnits.h>
 
@@ -40,7 +40,7 @@ public:
     }
 
 private:
-    WeakPtr<PaintableBox> m_paintable_box;
+    GC::Weak<PaintableBox> m_paintable_box;
     size_t m_id { 0 };
     bool m_sticky { false };
     RefPtr<ScrollFrame const> m_parent;
diff --git a/Libraries/LibWeb/ResizeObserver/ResizeObserver.h b/Libraries/LibWeb/ResizeObserver/ResizeObserver.h
index b5b6ab1592a..040d658120d 100644
--- a/Libraries/LibWeb/ResizeObserver/ResizeObserver.h
+++ b/Libraries/LibWeb/ResizeObserver/ResizeObserver.h
@@ -52,7 +52,7 @@ private:
     Vector<GC::Ref<ResizeObservation>> m_skipped_targets;
 
     // AD-HOC: This is the document where we've registered the observer.
-    WeakPtr<DOM::Document> m_document;
+    GC::Weak<DOM::Document> m_document;
 
     IntrusiveListNode<ResizeObserver> m_list_node;
 
diff --git a/Libraries/LibWeb/WebSockets/WebSocket.cpp b/Libraries/LibWeb/WebSockets/WebSocket.cpp
index 1f188ab6215..f929e9c956a 100644
--- a/Libraries/LibWeb/WebSockets/WebSocket.cpp
+++ b/Libraries/LibWeb/WebSockets/WebSocket.cpp
@@ -218,25 +218,25 @@ ErrorOr<void> WebSocket::establish_web_socket_connection(URL::URL const& url_rec
 
     m_websocket = request_client->websocket_connect(url_record, origin_string, protocol_byte_strings, {}, additional_headers);
 
-    m_websocket->on_open = [weak_this = make_weak_ptr<WebSocket>()] {
+    m_websocket->on_open = [weak_this = GC::Weak { *this }] {
         if (!weak_this)
             return;
         auto& websocket = const_cast<WebSocket&>(*weak_this);
         websocket.on_open();
     };
-    m_websocket->on_message = [weak_this = make_weak_ptr<WebSocket>()](auto message) {
+    m_websocket->on_message = [weak_this = GC::Weak { *this }](auto message) {
         if (!weak_this)
             return;
         auto& websocket = const_cast<WebSocket&>(*weak_this);
         websocket.on_message(move(message.data), message.is_text);
     };
-    m_websocket->on_close = [weak_this = make_weak_ptr<WebSocket>()](auto code, auto reason, bool was_clean) {
+    m_websocket->on_close = [weak_this = GC::Weak { *this }](auto code, auto reason, bool was_clean) {
         if (!weak_this)
             return;
         auto& websocket = const_cast<WebSocket&>(*weak_this);
         websocket.on_close(code, String::from_byte_string(reason).release_value_but_fixme_should_propagate_errors(), was_clean);
     };
-    m_websocket->on_error = [weak_this = make_weak_ptr<WebSocket>()](auto) {
+    m_websocket->on_error = [weak_this = GC::Weak { *this }](auto) {
         if (!weak_this)
             return;
         auto& websocket = const_cast<WebSocket&>(*weak_this);
diff --git a/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp b/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
index 4119454401f..2d03d71a60e 100644
--- a/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
+++ b/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
@@ -4471,7 +4471,7 @@ JS_DEFINE_NATIVE_FUNCTION(@class_name@::@attribute.setter_callback@)
                     //     1. Append a weak reference to element to elements.
                     // 5. Set this's explicitly set attr-elements to elements.
                     attribute_generator.append(R"~~~(
-    Vector<WeakPtr<DOM::Element>> elements;
+    Vector<GC::Weak<DOM::Element>> elements;
     elements.ensure_capacity(cpp_value->size());
 
     for (auto const& element : *cpp_value) {
diff --git a/Tests/LibWeb/Crash/CSS/media-query-evaluation-without-window.html b/Tests/LibWeb/Crash/CSS/media-query-evaluation-without-window.html
new file mode 100644
index 00000000000..dd4a203cbfd
--- /dev/null
+++ b/Tests/LibWeb/Crash/CSS/media-query-evaluation-without-window.html
@@ -0,0 +1,6 @@
+<!DOCTYPE html>
+<html>
+    <script>
+        const dom = new DOMParser().parseFromString(`<style media="width < 50px">`, "text/html");
+    </script>
+</html>
diff --git a/Tests/LibWeb/Text/expected/wpt-import/html/canvas/element/drawing-rectangles-to-the-canvas/2d.clearRect.nonfinite.txt b/Tests/LibWeb/Text/expected/wpt-import/html/canvas/element/drawing-rectangles-to-the-canvas/2d.clearRect.nonfinite.txt
new file mode 100644
index 00000000000..d4954b563c8
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/wpt-import/html/canvas/element/drawing-rectangles-to-the-canvas/2d.clearRect.nonfinite.txt
@@ -0,0 +1,6 @@
+Harness status: OK
+
+Found 1 tests
+
+1 Pass
+Pass	clearRect() with Infinity/NaN is ignored
\ No newline at end of file
diff --git a/Tests/LibWeb/Text/input/wpt-import/html/canvas/element/drawing-rectangles-to-the-canvas/2d.clearRect.nonfinite.html b/Tests/LibWeb/Text/input/wpt-import/html/canvas/element/drawing-rectangles-to-the-canvas/2d.clearRect.nonfinite.html
new file mode 100644
index 00000000000..57c62f33585
--- /dev/null
+++ b/Tests/LibWeb/Text/input/wpt-import/html/canvas/element/drawing-rectangles-to-the-canvas/2d.clearRect.nonfinite.html
@@ -0,0 +1,52 @@
+<!DOCTYPE html>
+<!-- DO NOT EDIT! This test has been generated by /html/canvas/tools/gentest.py. -->
+<meta charset="UTF-8">
+<title>Canvas test: 2d.clearRect.nonfinite</title>
+<script src="../../../../resources/testharness.js"></script>
+<script src="../../../../resources/testharnessreport.js"></script>
+<script src="../../../../html/canvas/resources/canvas-tests.js"></script>
+<link rel="stylesheet" href="../../../../html/canvas/resources/canvas-tests.css">
+<body class="show_output">
+
+<h1>2d.clearRect.nonfinite</h1>
+<p class="desc">clearRect() with Infinity/NaN is ignored</p>
+
+
+<p class="output">Actual output:</p>
+<canvas id="c" class="output" width="100" height="50"><p class="fallback">FAIL (fallback content)</p></canvas>
+<p class="output expectedtext">Expected output:<p><img src="../../../../images/green-100x50.png" class="output expected" id="expected" alt="">
+<ul id="d"></ul>
+<script>
+var t = async_test("clearRect() with Infinity/NaN is ignored");
+_addTest(function(canvas, ctx) {
+
+  ctx.fillStyle = '#0f0';
+  ctx.fillRect(0, 0, 100, 50);
+  ctx.clearRect(Infinity, 0, 100, 50);
+  ctx.clearRect(-Infinity, 0, 100, 50);
+  ctx.clearRect(NaN, 0, 100, 50);
+  ctx.clearRect(0, Infinity, 100, 50);
+  ctx.clearRect(0, -Infinity, 100, 50);
+  ctx.clearRect(0, NaN, 100, 50);
+  ctx.clearRect(0, 0, Infinity, 50);
+  ctx.clearRect(0, 0, -Infinity, 50);
+  ctx.clearRect(0, 0, NaN, 50);
+  ctx.clearRect(0, 0, 100, Infinity);
+  ctx.clearRect(0, 0, 100, -Infinity);
+  ctx.clearRect(0, 0, 100, NaN);
+  ctx.clearRect(Infinity, Infinity, 100, 50);
+  ctx.clearRect(Infinity, Infinity, Infinity, 50);
+  ctx.clearRect(Infinity, Infinity, Infinity, Infinity);
+  ctx.clearRect(Infinity, Infinity, 100, Infinity);
+  ctx.clearRect(Infinity, 0, Infinity, 50);
+  ctx.clearRect(Infinity, 0, Infinity, Infinity);
+  ctx.clearRect(Infinity, 0, 100, Infinity);
+  ctx.clearRect(0, Infinity, Infinity, 50);
+  ctx.clearRect(0, Infinity, Infinity, Infinity);
+  ctx.clearRect(0, Infinity, 100, Infinity);
+  ctx.clearRect(0, 0, Infinity, Infinity);
+  _assertPixel(canvas, 50,25, 0,255,0,255);
+
+});
+</script>
+