diff --git a/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp b/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
index 8e4f0360f5..d0aa9a33d5 100644
--- a/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
+++ b/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
@@ -139,7 +139,7 @@ CppType idl_type_name_to_cpp_type(Type const& type, Interface const& interface)
         return { .name = "JS::Handle<JS::Object>", .sequence_storage_type = SequenceStorageType::MarkedVector };
 
     if (type.name() == "File")
-        return { .name = "JS::NonnullGCPtr<FileAPI::File>", .sequence_storage_type = SequenceStorageType::MarkedVector };
+        return { .name = "JS::Handle<FileAPI::File>", .sequence_storage_type = SequenceStorageType::MarkedVector };
 
     if (type.name() == "sequence") {
         auto& parameterized_type = verify_cast<ParameterizedType>(type);
diff --git a/Userland/Libraries/LibWeb/HTML/FormControlInfrastructure.cpp b/Userland/Libraries/LibWeb/HTML/FormControlInfrastructure.cpp
index dd60727a4c..73cefdfaeb 100644
--- a/Userland/Libraries/LibWeb/HTML/FormControlInfrastructure.cpp
+++ b/Userland/Libraries/LibWeb/HTML/FormControlInfrastructure.cpp
@@ -15,7 +15,7 @@
 namespace Web::HTML {
 
 // https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#create-an-entry
-WebIDL::ExceptionOr<Entry> create_entry(JS::Realm& realm, String const& name, Variant<JS::NonnullGCPtr<FileAPI::Blob>, String> const& value, Optional<String> const& filename)
+WebIDL::ExceptionOr<XHR::FormDataEntry> create_entry(JS::Realm& realm, String const& name, Variant<JS::NonnullGCPtr<FileAPI::Blob>, String> const& value, Optional<String> const& filename)
 {
     auto& vm = realm.vm();
 
@@ -24,11 +24,11 @@ WebIDL::ExceptionOr<Entry> create_entry(JS::Realm& realm, String const& name, Va
 
     auto entry_value = TRY(value.visit(
         // 2. If value is a string, then set value to the result of converting value into a scalar value string.
-        [&](String const& string) -> WebIDL::ExceptionOr<Variant<JS::NonnullGCPtr<FileAPI::File>, String>> {
+        [&](String const& string) -> WebIDL::ExceptionOr<Variant<JS::Handle<FileAPI::File>, String>> {
             return TRY_OR_THROW_OOM(vm, Infra::convert_to_scalar_value_string(string));
         },
         // 3. Otherwise:
-        [&](JS::NonnullGCPtr<FileAPI::Blob> const& blob) -> WebIDL::ExceptionOr<Variant<JS::NonnullGCPtr<FileAPI::File>, String>> {
+        [&](JS::NonnullGCPtr<FileAPI::Blob> const& blob) -> WebIDL::ExceptionOr<Variant<JS::Handle<FileAPI::File>, String>> {
             // 1. If value is not a File object, then set value to a new File object, representing the same bytes, whose name attribute value is "blob".
             // 2. If filename is given, then set value to a new File object, representing the same bytes, whose name attribute is filename.
             String name_attribute;
@@ -36,11 +36,11 @@ WebIDL::ExceptionOr<Entry> create_entry(JS::Realm& realm, String const& name, Va
                 name_attribute = filename.value();
             else
                 name_attribute = TRY_OR_THROW_OOM(vm, String::from_utf8("blob"sv));
-            return TRY(FileAPI::File::create(realm, { JS::make_handle(*blob) }, name_attribute.to_deprecated_string(), {}));
+            return JS::make_handle(TRY(FileAPI::File::create(realm, { JS::make_handle(*blob) }, name_attribute.to_deprecated_string(), {})));
         }));
 
     // 4. Return an entry whose name is name and whose value is value.
-    return Entry {
+    return XHR::FormDataEntry {
         .name = move(entry_name),
         .value = move(entry_value),
     };
@@ -48,13 +48,13 @@ WebIDL::ExceptionOr<Entry> create_entry(JS::Realm& realm, String const& name, Va
 
 // https://html.spec.whatwg.org/multipage/form-control-infrastructure.html#constructing-the-form-data-set
 // FIXME: Add missing parameters optional submitter, and optional encoding
-WebIDL::ExceptionOr<Optional<HashMapWithVectorOfFormDataEntryValue>> construct_entry_list(JS::Realm& realm, HTMLFormElement& form)
+WebIDL::ExceptionOr<Optional<Vector<XHR::FormDataEntry>>> construct_entry_list(JS::Realm& realm, HTMLFormElement& form)
 {
     auto& vm = realm.vm();
 
     // 1. If form's constructing entry list is true, then return null.
     if (form.constructing_entry_list())
-        return Optional<HashMapWithVectorOfFormDataEntryValue> {};
+        return Optional<Vector<XHR::FormDataEntry>> {};
 
     // 2. Set form's constructing entry list to true.
     form.set_constructing_entry_list(true);
@@ -63,7 +63,7 @@ WebIDL::ExceptionOr<Optional<HashMapWithVectorOfFormDataEntryValue>> construct_e
     auto controls = TRY_OR_THROW_OOM(vm, form.get_submittable_elements());
 
     // 4. Let entry list be a new empty entry list.
-    HashMapWithVectorOfFormDataEntryValue entry_list;
+    Vector<XHR::FormDataEntry> entry_list;
 
     // 5. For each element field in controls, in tree order:
     for (auto const& control : controls) {
@@ -101,19 +101,17 @@ WebIDL::ExceptionOr<Optional<HashMapWithVectorOfFormDataEntryValue>> construct_e
             continue;
 
         // 5. Let name be the value of the field element's name attribute.
-        auto name = control->name();
-
-        auto form_data_entries = entry_list.contains(name) && entry_list.get(name).has_value()
-            ? entry_list.get(name).value()
-            : Vector<XHR::FormDataEntryValue> {};
+        auto name = TRY_OR_THROW_OOM(vm, String::from_deprecated_string(control->name()));
 
         // 6. If the field element is a select element, then for each option element in the select element's list of options whose selectedness is true and that is not disabled, create an entry with name and the value of the option element, and append it to entry list.
         if (auto* select_element = dynamic_cast<HTML::HTMLSelectElement*>(control.ptr())) {
             for (auto const& option_element : select_element->list_of_options()) {
-                if (option_element->selected() && !option_element->disabled())
-                    TRY_OR_THROW_OOM(vm, form_data_entries.try_append(option_element->value()));
+                if (option_element->selected() && !option_element->disabled()) {
+                    auto option_name = TRY_OR_THROW_OOM(vm, String::from_deprecated_string(option_element->name()));
+                    auto option_value = TRY_OR_THROW_OOM(vm, String::from_deprecated_string(option_element->value()));
+                    TRY_OR_THROW_OOM(vm, entry_list.try_append(XHR::FormDataEntry { .name = move(option_name), .value = move(option_value) }));
+                }
             }
-            TRY_OR_THROW_OOM(vm, entry_list.try_set(name, form_data_entries));
         }
         // 7. Otherwise, if the field element is an input element whose type attribute is in the Checkbox state or the Radio Button state, then:
         else if (auto* checkbox_or_radio_element = dynamic_cast<HTML::HTMLInputElement*>(control.ptr()); checkbox_or_radio_element && (checkbox_or_radio_element->type() == "checkbox" || checkbox_or_radio_element->type() == "radio") && checkbox_or_radio_element->checked()) {
@@ -123,8 +121,9 @@ WebIDL::ExceptionOr<Optional<HashMapWithVectorOfFormDataEntryValue>> construct_e
                 value = "on";
 
             // 2. Create an entry with name and value, and append it to entry list.
-            TRY_OR_THROW_OOM(vm, form_data_entries.try_append(value));
-            TRY_OR_THROW_OOM(vm, entry_list.try_set(name, form_data_entries));
+            auto checkbox_or_radio_element_name = TRY_OR_THROW_OOM(vm, String::from_deprecated_string(checkbox_or_radio_element->name()));
+            auto checkbox_or_radio_element_value = TRY_OR_THROW_OOM(vm, String::from_deprecated_string(value));
+            TRY_OR_THROW_OOM(vm, entry_list.try_append(XHR::FormDataEntry { .name = move(checkbox_or_radio_element_name), .value = move(checkbox_or_radio_element_value) }));
         }
         // 8. Otherwise, if the field element is an input element whose type attribute is in the File Upload state, then:
         else if (auto* file_element = dynamic_cast<HTML::HTMLInputElement*>(control.ptr()); file_element && file_element->type() == "file") {
@@ -133,16 +132,14 @@ WebIDL::ExceptionOr<Optional<HashMapWithVectorOfFormDataEntryValue>> construct_e
                 FileAPI::FilePropertyBag options {};
                 options.type = "application/octet-stream";
                 auto file = TRY(FileAPI::File::create(realm, {}, "", options));
-                TRY_OR_THROW_OOM(vm, form_data_entries.try_append(file));
-                TRY_OR_THROW_OOM(vm, entry_list.try_set(name, form_data_entries));
+                TRY_OR_THROW_OOM(vm, entry_list.try_append(XHR::FormDataEntry { .name = move(name), .value = JS::make_handle(file) }));
             }
             // 2. Otherwise, for each file in selected files, create an entry with name and a File object representing the file, and append it to entry list.
             else {
                 for (size_t i = 0; i < file_element->files()->length(); i++) {
                     auto file = JS::NonnullGCPtr { *file_element->files()->item(i) };
-                    TRY_OR_THROW_OOM(vm, form_data_entries.try_append(file));
+                    TRY_OR_THROW_OOM(vm, entry_list.try_append(XHR::FormDataEntry { .name = move(name), .value = JS::make_handle(file) }));
                 }
-                TRY_OR_THROW_OOM(vm, entry_list.try_set(name, form_data_entries));
             }
         }
         // FIXME: 9. Otherwise, if the field element is an input element whose type attribute is in the Hidden state and name is an ASCII case-insensitive match for "_charset_":
@@ -152,8 +149,8 @@ WebIDL::ExceptionOr<Optional<HashMapWithVectorOfFormDataEntryValue>> construct_e
         else {
             auto* element = dynamic_cast<HTML::HTMLElement*>(control.ptr());
             VERIFY(element);
-            TRY_OR_THROW_OOM(vm, form_data_entries.try_append(element->attribute("value"sv)));
-            TRY_OR_THROW_OOM(vm, entry_list.try_set(name, form_data_entries));
+            auto value_attribute = TRY_OR_THROW_OOM(vm, String::from_deprecated_string(element->attribute("value"sv)));
+            TRY_OR_THROW_OOM(vm, entry_list.try_append(XHR::FormDataEntry { .name = move(name), .value = move(value_attribute) }));
         }
 
         // FIXME: 11. If the element has a dirname attribute, and that attribute's value is not the empty string, then:
@@ -175,7 +172,7 @@ WebIDL::ExceptionOr<Optional<HashMapWithVectorOfFormDataEntryValue>> construct_e
     form.set_constructing_entry_list(false);
 
     // 9. Return a clone of entry list.
-    return TRY_OR_THROW_OOM(vm, entry_list.clone());
+    return entry_list;
 }
 
 }
diff --git a/Userland/Libraries/LibWeb/HTML/FormControlInfrastructure.h b/Userland/Libraries/LibWeb/HTML/FormControlInfrastructure.h
index 3ea46634e5..493b568198 100644
--- a/Userland/Libraries/LibWeb/HTML/FormControlInfrastructure.h
+++ b/Userland/Libraries/LibWeb/HTML/FormControlInfrastructure.h
@@ -10,14 +10,7 @@
 
 namespace Web::HTML {
 
-using HashMapWithVectorOfFormDataEntryValue = HashMap<DeprecatedString, Vector<XHR::FormDataEntryValue>>;
-
-struct Entry {
-    String name;
-    Variant<JS::NonnullGCPtr<FileAPI::File>, String> value;
-};
-
-WebIDL::ExceptionOr<Entry> create_entry(JS::Realm& realm, String const& name, Variant<JS::NonnullGCPtr<FileAPI::Blob>, String> const& value, Optional<String> const& filename = {});
-WebIDL::ExceptionOr<Optional<HashMapWithVectorOfFormDataEntryValue>> construct_entry_list(JS::Realm&, HTMLFormElement&);
+WebIDL::ExceptionOr<XHR::FormDataEntry> create_entry(JS::Realm& realm, String const& name, Variant<JS::NonnullGCPtr<FileAPI::Blob>, String> const& value, Optional<String> const& filename = {});
+WebIDL::ExceptionOr<Optional<Vector<XHR::FormDataEntry>>> construct_entry_list(JS::Realm&, HTMLFormElement&);
 
 }
diff --git a/Userland/Libraries/LibWeb/XHR/FormData.cpp b/Userland/Libraries/LibWeb/XHR/FormData.cpp
index 19722689bc..d2fca57323 100644
--- a/Userland/Libraries/LibWeb/XHR/FormData.cpp
+++ b/Userland/Libraries/LibWeb/XHR/FormData.cpp
@@ -18,7 +18,7 @@ namespace Web::XHR {
 // https://xhr.spec.whatwg.org/#dom-formdata
 WebIDL::ExceptionOr<JS::NonnullGCPtr<FormData>> FormData::construct_impl(JS::Realm& realm, Optional<JS::NonnullGCPtr<HTML::HTMLFormElement>> form)
 {
-    HashMap<DeprecatedString, Vector<FormDataEntryValue>> list;
+    Vector<FormDataEntry> list;
     // 1. If form is given, then:
     if (form.has_value()) {
         // 1. Let list be the result of constructing the entry list for form.
@@ -33,12 +33,12 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<FormData>> FormData::construct_impl(JS::Rea
     return construct_impl(realm, move(list));
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<FormData>> FormData::construct_impl(JS::Realm& realm, HashMap<DeprecatedString, Vector<FormDataEntryValue>> entry_list)
+WebIDL::ExceptionOr<JS::NonnullGCPtr<FormData>> FormData::construct_impl(JS::Realm& realm, Vector<FormDataEntry> entry_list)
 {
     return MUST_OR_THROW_OOM(realm.heap().allocate<FormData>(realm, realm, move(entry_list)));
 }
 
-FormData::FormData(JS::Realm& realm, HashMap<DeprecatedString, Vector<FormDataEntryValue>> entry_list)
+FormData::FormData(JS::Realm& realm, Vector<FormDataEntry> entry_list)
     : PlatformObject(realm)
     , m_entry_list(move(entry_list))
 {
@@ -54,30 +54,17 @@ JS::ThrowCompletionOr<void> FormData::initialize(JS::Realm& realm)
     return {};
 }
 
-void FormData::visit_edges(Cell::Visitor& visitor)
-{
-    Base::visit_edges(visitor);
-    for (auto const& entry : m_entry_list) {
-        for (auto const& value : entry.value) {
-            if (auto* file = value.get_pointer<JS::NonnullGCPtr<FileAPI::File>>())
-                visitor.visit(*file);
-        }
-    }
-}
-
 // https://xhr.spec.whatwg.org/#dom-formdata-append
-WebIDL::ExceptionOr<void> FormData::append(DeprecatedString const& name, DeprecatedString const& value)
+WebIDL::ExceptionOr<void> FormData::append(String const& name, String const& value)
 {
-    auto& vm = realm().vm();
-    return append_impl(TRY_OR_THROW_OOM(vm, String::from_deprecated_string(name)), TRY_OR_THROW_OOM(vm, String::from_deprecated_string(value)));
+    return append_impl(name, value);
 }
 
 // https://xhr.spec.whatwg.org/#dom-formdata-append-blob
-WebIDL::ExceptionOr<void> FormData::append(DeprecatedString const& name, JS::NonnullGCPtr<FileAPI::Blob> const& blob_value, Optional<DeprecatedString> const& filename)
+WebIDL::ExceptionOr<void> FormData::append(String const& name, JS::NonnullGCPtr<FileAPI::Blob> const& blob_value, Optional<String> const& filename)
 {
-    auto& vm = realm().vm();
-    auto inner_filename = filename.has_value() ? TRY_OR_THROW_OOM(vm, String::from_deprecated_string(filename.value())) : Optional<String> {};
-    return append_impl(TRY_OR_THROW_OOM(vm, String::from_deprecated_string(name)), blob_value, inner_filename);
+    auto inner_filename = filename.has_value() ? filename.value() : Optional<String> {};
+    return append_impl(name, blob_value, inner_filename);
 }
 
 // https://xhr.spec.whatwg.org/#dom-formdata-append
@@ -91,67 +78,67 @@ WebIDL::ExceptionOr<void> FormData::append_impl(String const& name, Variant<JS::
     // 2. Let entry be the result of creating an entry with name, value, and filename if given.
     auto entry = TRY(HTML::create_entry(realm, name, value, filename));
 
-    // FIXME: Remove this when our binding generator supports "new string".
-    auto form_data_entry_value = entry.value.has<String>()
-        ? FormDataEntryValue { entry.value.get<String>().to_deprecated_string() }
-        : FormDataEntryValue { entry.value.get<JS::NonnullGCPtr<FileAPI::File>>() };
-
     // 3. Append entry to this’s entry list.
-    if (auto entries = m_entry_list.get(entry.name.to_deprecated_string()); entries.has_value() && !entries->is_empty())
-        TRY_OR_THROW_OOM(vm, entries->try_append(form_data_entry_value));
-    else
-        TRY_OR_THROW_OOM(vm, m_entry_list.try_set(entry.name.to_deprecated_string(), { form_data_entry_value }));
-
+    TRY_OR_THROW_OOM(vm, m_entry_list.try_append(move(entry)));
     return {};
 }
 
 // https://xhr.spec.whatwg.org/#dom-formdata-delete
-void FormData::delete_(DeprecatedString const& name)
+void FormData::delete_(String const& name)
 {
     // The delete(name) method steps are to remove all entries whose name is name from this’s entry list.
-    m_entry_list.remove(name);
+    m_entry_list.remove_all_matching([&name](FormDataEntry const& entry) {
+        return entry.name == name;
+    });
 }
 
 // https://xhr.spec.whatwg.org/#dom-formdata-get
-Variant<JS::NonnullGCPtr<FileAPI::File>, DeprecatedString, Empty> FormData::get(DeprecatedString const& name)
+Variant<JS::Handle<FileAPI::File>, String, Empty> FormData::get(String const& name)
 {
     // 1. If there is no entry whose name is name in this’s entry list, then return null.
-    if (!m_entry_list.contains(name))
+    auto entry_iterator = m_entry_list.find_if([&name](FormDataEntry const& entry) {
+        return entry.name == name;
+    });
+    if (entry_iterator.is_end())
         return Empty {};
     // 2. Return the value of the first entry whose name is name from this’s entry list.
-    return m_entry_list.get(name)->at(0);
+    return entry_iterator->value;
 }
 
 // https://xhr.spec.whatwg.org/#dom-formdata-getall
-Vector<FormDataEntryValue> FormData::get_all(DeprecatedString const& name)
+WebIDL::ExceptionOr<Vector<FormDataEntryValue>> FormData::get_all(String const& name)
 {
     // 1. If there is no entry whose name is name in this’s entry list, then return the empty list.
-    if (!m_entry_list.contains(name))
-        return {};
     // 2. Return the values of all entries whose name is name, in order, from this’s entry list.
-    return *m_entry_list.get(name);
+    Vector<FormDataEntryValue> values;
+    for (auto const& entry : m_entry_list) {
+        if (entry.name == name)
+            TRY_OR_THROW_OOM(vm(), values.try_append(entry.value));
+    }
+    return values;
 }
 
 // https://xhr.spec.whatwg.org/#dom-formdata-has
-bool FormData::has(DeprecatedString const& name)
+bool FormData::has(String const& name)
 {
     // The has(name) method steps are to return true if there is an entry whose name is name in this’s entry list; otherwise false.
-    return m_entry_list.contains(name);
+    return !m_entry_list.find_if([&name](auto& entry) {
+                            return entry.name == name;
+                        })
+                .is_end();
 }
 
 // https://xhr.spec.whatwg.org/#dom-formdata-set
-WebIDL::ExceptionOr<void> FormData::set(DeprecatedString const& name, DeprecatedString const& value)
+WebIDL::ExceptionOr<void> FormData::set(String const& name, String const& value)
 {
-    auto& vm = realm().vm();
-    return set_impl(TRY_OR_THROW_OOM(vm, String::from_deprecated_string(name)), TRY_OR_THROW_OOM(vm, String::from_deprecated_string(value)));
+    return set_impl(name, value);
 }
 
 // https://xhr.spec.whatwg.org/#dom-formdata-set-blob
-WebIDL::ExceptionOr<void> FormData::set(DeprecatedString const& name, JS::NonnullGCPtr<FileAPI::Blob> const& blob_value, Optional<DeprecatedString> const& filename)
+WebIDL::ExceptionOr<void> FormData::set(String const& name, JS::NonnullGCPtr<FileAPI::Blob> const& blob_value, Optional<String> const& filename)
 {
-    auto& vm = realm().vm();
-    auto inner_filename = filename.has_value() ? TRY_OR_THROW_OOM(vm, String::from_deprecated_string(filename.value())) : Optional<String> {};
-    return set_impl(TRY_OR_THROW_OOM(vm, String::from_deprecated_string(name)), blob_value, inner_filename);
+    auto inner_filename = filename.has_value() ? filename.value() : Optional<String> {};
+    return set_impl(name, blob_value, inner_filename);
 }
 
 // https://xhr.spec.whatwg.org/#dom-formdata-set
@@ -165,19 +152,20 @@ WebIDL::ExceptionOr<void> FormData::set_impl(String const& name, Variant<JS::Non
     // 2. Let entry be the result of creating an entry with name, value, and filename if given.
     auto entry = TRY(HTML::create_entry(realm, name, value, filename));
 
-    // FIXME: Remove this when our binding generator supports "new string".
-    auto form_data_entry_value = entry.value.has<String>()
-        ? FormDataEntryValue { entry.value.get<String>().to_deprecated_string() }
-        : FormDataEntryValue { entry.value.get<JS::NonnullGCPtr<FileAPI::File>>() };
+    auto existing = m_entry_list.find_if([&name](auto& entry) {
+        return entry.name == name;
+    });
 
     // 3. If there are entries in this’s entry list whose name is name, then replace the first such entry with entry and remove the others.
-    if (auto entries = m_entry_list.get(entry.name.to_deprecated_string()); entries.has_value() && !entries->is_empty()) {
-        entries->remove(0, entries->size());
-        TRY_OR_THROW_OOM(vm, entries->try_append(form_data_entry_value));
+    if (!existing.is_end()) {
+        existing->value = entry.value;
+        m_entry_list.remove_all_matching([&name, &existing](auto& entry) {
+            return &entry != &*existing && entry.name == name;
+        });
     }
     // 4. Otherwise, append entry to this’s entry list.
     else {
-        TRY_OR_THROW_OOM(vm, m_entry_list.try_set(entry.name.to_deprecated_string(), { form_data_entry_value }));
+        TRY_OR_THROW_OOM(vm, m_entry_list.try_append(move(entry)));
     }
 
     return {};
diff --git a/Userland/Libraries/LibWeb/XHR/FormData.h b/Userland/Libraries/LibWeb/XHR/FormData.h
index 99171309a6..b8a3f300ef 100644
--- a/Userland/Libraries/LibWeb/XHR/FormData.h
+++ b/Userland/Libraries/LibWeb/XHR/FormData.h
@@ -15,7 +15,12 @@
 namespace Web::XHR {
 
 // https://xhr.spec.whatwg.org/#formdataentryvalue
-using FormDataEntryValue = Variant<JS::NonnullGCPtr<FileAPI::File>, DeprecatedString>;
+using FormDataEntryValue = Variant<JS::Handle<FileAPI::File>, String>;
+
+struct FormDataEntry {
+    String name;
+    FormDataEntryValue value;
+};
 
 // https://xhr.spec.whatwg.org/#interface-formdata
 class FormData : public Bindings::PlatformObject {
@@ -25,27 +30,26 @@ public:
     virtual ~FormData() override;
 
     static WebIDL::ExceptionOr<JS::NonnullGCPtr<FormData>> construct_impl(JS::Realm&, Optional<JS::NonnullGCPtr<HTML::HTMLFormElement>> form = {});
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<FormData>> construct_impl(JS::Realm&, HashMap<DeprecatedString, Vector<FormDataEntryValue>> entry_list);
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<FormData>> construct_impl(JS::Realm&, Vector<FormDataEntry> entry_list);
 
-    WebIDL::ExceptionOr<void> append(DeprecatedString const& name, DeprecatedString const& value);
-    WebIDL::ExceptionOr<void> append(DeprecatedString const& name, JS::NonnullGCPtr<FileAPI::Blob> const& blob_value, Optional<DeprecatedString> const& filename = {});
-    void delete_(DeprecatedString const& name);
-    Variant<JS::NonnullGCPtr<FileAPI::File>, DeprecatedString, Empty> get(DeprecatedString const& name);
-    Vector<FormDataEntryValue> get_all(DeprecatedString const& name);
-    bool has(DeprecatedString const& name);
-    WebIDL::ExceptionOr<void> set(DeprecatedString const& name, DeprecatedString const& value);
-    WebIDL::ExceptionOr<void> set(DeprecatedString const& name, JS::NonnullGCPtr<FileAPI::Blob> const& blob_value, Optional<DeprecatedString> const& filename = {});
+    WebIDL::ExceptionOr<void> append(String const& name, String const& value);
+    WebIDL::ExceptionOr<void> append(String const& name, JS::NonnullGCPtr<FileAPI::Blob> const& blob_value, Optional<String> const& filename = {});
+    void delete_(String const& name);
+    Variant<JS::Handle<FileAPI::File>, String, Empty> get(String const& name);
+    WebIDL::ExceptionOr<Vector<FormDataEntryValue>> get_all(String const& name);
+    bool has(String const& name);
+    WebIDL::ExceptionOr<void> set(String const& name, String const& value);
+    WebIDL::ExceptionOr<void> set(String const& name, JS::NonnullGCPtr<FileAPI::Blob> const& blob_value, Optional<String> const& filename = {});
 
 private:
-    explicit FormData(JS::Realm&, HashMap<DeprecatedString, Vector<FormDataEntryValue>> entry_list = {});
+    explicit FormData(JS::Realm&, Vector<FormDataEntry> entry_list = {});
 
     virtual JS::ThrowCompletionOr<void> initialize(JS::Realm&) override;
-    virtual void visit_edges(Cell::Visitor&) override;
 
     WebIDL::ExceptionOr<void> append_impl(String const& name, Variant<JS::NonnullGCPtr<FileAPI::Blob>, String> const& value, Optional<String> const& filename = {});
     WebIDL::ExceptionOr<void> set_impl(String const& name, Variant<JS::NonnullGCPtr<FileAPI::Blob>, String> const& value, Optional<String> const& filename = {});
 
-    HashMap<DeprecatedString, Vector<FormDataEntryValue>> m_entry_list;
+    Vector<FormDataEntry> m_entry_list;
 };
 
 }
diff --git a/Userland/Libraries/LibWeb/XHR/FormData.idl b/Userland/Libraries/LibWeb/XHR/FormData.idl
index ca5b170026..38af410dfc 100644
--- a/Userland/Libraries/LibWeb/XHR/FormData.idl
+++ b/Userland/Libraries/LibWeb/XHR/FormData.idl
@@ -5,7 +5,7 @@
 typedef (File or USVString) FormDataEntryValue;
 
 // https://xhr.spec.whatwg.org/#interface-formdata
-[Exposed=Window]
+[Exposed=Window, UseNewAKString]
 interface FormData {
     constructor(optional HTMLFormElement form);