diff --git a/Libraries/LibWeb/CMakeLists.txt b/Libraries/LibWeb/CMakeLists.txt
index 811736f30a2..d023a527a66 100644
--- a/Libraries/LibWeb/CMakeLists.txt
+++ b/Libraries/LibWeb/CMakeLists.txt
@@ -33,6 +33,7 @@ set(SOURCES
     Bindings/SyntheticHostDefined.cpp
     Clipboard/Clipboard.cpp
     Clipboard/ClipboardEvent.cpp
+    Clipboard/ClipboardItem.cpp
     Compression/CompressionStream.cpp
     Compression/DecompressionStream.cpp
     Crypto/Crypto.cpp
diff --git a/Libraries/LibWeb/Clipboard/ClipboardItem.cpp b/Libraries/LibWeb/Clipboard/ClipboardItem.cpp
new file mode 100644
index 00000000000..b060238c7f6
--- /dev/null
+++ b/Libraries/LibWeb/Clipboard/ClipboardItem.cpp
@@ -0,0 +1,208 @@
+/*
+ * Copyright (c) 2024, Feng Yu <f3n67u@outlook.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibJS/Runtime/Realm.h>
+#include <LibWeb/Bindings/Intrinsics.h>
+#include <LibWeb/Clipboard/ClipboardItem.h>
+#include <LibWeb/FileAPI/Blob.h>
+#include <LibWeb/MimeSniff/MimeType.h>
+#include <LibWeb/WebIDL/Promise.h>
+
+namespace Web::Clipboard {
+
+GC_DEFINE_ALLOCATOR(ClipboardItem);
+
+// https://w3c.github.io/clipboard-apis/#dom-clipboarditem-clipboarditem
+WebIDL::ExceptionOr<GC::Ref<ClipboardItem>> ClipboardItem::construct_impl(JS::Realm& realm, OrderedHashMap<String, GC::Root<WebIDL::Promise>> const& items, ClipboardItemOptions const& options)
+{
+    // 1. If items is empty, then throw a TypeError.
+    if (items.is_empty())
+        return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, "Items cannot be empty"sv };
+
+    // 2. If options is empty, then set options["presentationStyle"] = "unspecified".
+    // NOTE: This step is handled by presentationStyle's default value in ClipboardItemOptions.
+
+    // 3. Set this's clipboard item to a new clipboard item.
+    auto clipboard_item = realm.create<ClipboardItem>(realm);
+
+    // 4. Set this's clipboard item's presentation style to options["presentationStyle"].
+    clipboard_item->m_presentation_style = options.presentation_style;
+
+    // 5. Let types be a list of DOMString.
+    Vector<String> types;
+
+    // 6. For each (key, value) in items:
+    for (auto const& [key, value] : items) {
+        // 2. Let isCustom be false.
+        bool is_custom = false;
+
+        // 3. If key starts with `"web "` prefix, then:
+        auto key_without_prefix = key;
+        if (key.starts_with_bytes(WEB_CUSTOM_FORMAT_PREFIX)) {
+            // 1. Remove `"web "` prefix and assign the remaining string to key.
+            key_without_prefix = MUST(key.substring_from_byte_offset(WEB_CUSTOM_FORMAT_PREFIX.length()));
+
+            // 2. Set isCustom to true.
+            is_custom = true;
+        }
+
+        // 5. Let mimeType be the result of parsing a MIME type given key.
+        auto mime_type = MimeSniff::MimeType::parse(key_without_prefix);
+
+        // 6. If mimeType is failure, then throw a TypeError.
+        if (!mime_type.has_value()) {
+            return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, MUST(String::formatted("Invalid MIME type: {}", key)) };
+        }
+
+        auto mime_type_serialized = mime_type->serialized();
+
+        // 7. If this's clipboard item's list of representations contains a representation whose MIME type
+        //    is mimeType and whose [representation/isCustom] is isCustom, then throw a TypeError.
+        auto existing = clipboard_item->m_representations.find_if([&](auto const& item) {
+            return item.mime_type == mime_type_serialized && item.is_custom == is_custom;
+        });
+        if (!existing.is_end()) {
+            return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, MUST(String::formatted("Duplicate MIME type: {}", key)) };
+        }
+
+        // 11. Let mimeTypeString be the result of serializing a MIME type with mimeType.
+        // 12. If isCustom is true, prefix mimeTypeString with `"web "`.
+        auto mime_type_string = is_custom ? MUST(String::formatted("{}{}", WEB_CUSTOM_FORMAT_PREFIX, mime_type_serialized)) : mime_type_serialized;
+
+        // 13. Add mimeTypeString to types.
+        types.append(move(mime_type_string));
+
+        // 1. Let representation be a new representation.
+        // 4. Set representation’s isCustom flag to isCustom.
+        // 8. Set representation’s MIME type to mimeType.
+        // 9. Set representation’s data to value.
+        // 10. Append representation to this's clipboard item's list of representations.
+        clipboard_item->m_representations.empend(move(mime_type_serialized), is_custom, *value);
+    }
+
+    // 7. Set this's types array to the result of running create a frozen array from types.
+    clipboard_item->m_types = types;
+
+    return clipboard_item;
+}
+
+// https://w3c.github.io/clipboard-apis/#dom-clipboarditem-gettype
+WebIDL::ExceptionOr<GC::Ref<WebIDL::Promise>> ClipboardItem::get_type(String const& type)
+{
+    // 1. Let realm be this's relevant realm.
+    auto& realm = HTML::relevant_realm(*this);
+
+    // 2. Let isCustom be false.
+    bool is_custom = false;
+
+    // 3. If type starts with `"web "` prefix, then:
+    auto type_without_prefix = type;
+    if (type.starts_with_bytes(WEB_CUSTOM_FORMAT_PREFIX)) {
+        // 1. Remove `"web "` prefix and assign the remaining string to type.
+        type_without_prefix = MUST(type.substring_from_byte_offset(WEB_CUSTOM_FORMAT_PREFIX.length()));
+
+        // 2. Set isCustom to true.
+        is_custom = true;
+    }
+
+    // 4. Let mimeType be the result of parsing a MIME type given type.
+    auto mime_type = MimeSniff::MimeType::parse(type_without_prefix);
+
+    // 5. If mimeType is failure, then throw a TypeError.
+    if (!mime_type.has_value()) {
+        return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, MUST(String::formatted("Invalid MIME type: {}", type)) };
+    }
+
+    auto mime_type_serialized = mime_type->serialized();
+
+    // 6. Let itemTypeList be this's clipboard item's list of representations.
+    auto const& item_type_list = m_representations;
+
+    // 7.  Let p be a new promise in realm.
+    auto promise = WebIDL::create_promise(realm);
+
+    // 8. For each representation in itemTypeList:
+    for (auto const& representation : item_type_list) {
+        // 1. If representation’s MIME type is mimeType and representation’s isCustom is isCustom, then:
+        if (representation.mime_type == mime_type_serialized && representation.is_custom == is_custom) {
+            // 1. Let representationDataPromise be the representation’s data.
+            auto representation_data_promise = representation.data;
+
+            // 2. React to representationDataPromise:
+            WebIDL::react_to_promise(
+                *representation_data_promise,
+                GC::create_function(realm.heap(), [&realm, promise, mime_type_serialized](JS::Value value) -> WebIDL::ExceptionOr<JS::Value> {
+                    // 1. If v is a DOMString, then follow the below steps:
+                    if (value.is_string()) {
+                        // 1. Let dataAsBytes be the result of UTF-8 encoding v.
+                        auto utf8_string = value.as_string().utf8_string();
+                        auto data_as_bytes = MUST(ByteBuffer::copy(utf8_string.bytes()));
+
+                        // 2. Let blobData be a Blob created using dataAsBytes with its type set to mimeType, serialized.
+                        auto blob_data = FileAPI::Blob::create(realm, data_as_bytes, mime_type_serialized);
+
+                        // 3. Resolve p with blobData.
+                        WebIDL::resolve_promise(realm, promise, blob_data);
+                    }
+                    // 2. If v is a Blob, then follow the below steps:
+                    if (value.is_object() && is<FileAPI::Blob>(value.as_object())) {
+                        // 1. Resolve p with v.
+                        WebIDL::resolve_promise(realm, promise, value);
+                    }
+
+                    return JS::js_undefined();
+                }),
+                // 2. If representationDataPromise was rejected, then:
+                GC::create_function(realm.heap(), [&realm, type, promise](JS::Value) -> WebIDL::ExceptionOr<JS::Value> {
+                    // 1. Reject p with "NotFoundError" DOMException in realm.
+                    WebIDL::reject_promise(realm, promise, WebIDL::NotFoundError::create(realm, MUST(String::formatted("No data found for MIME type: {}", type))));
+
+                    return JS::js_undefined();
+                }));
+
+            // 3. Return p.
+            return promise;
+        }
+    }
+
+    // 9. Reject p with "NotFoundError" DOMException in realm.
+    WebIDL::reject_promise(realm, promise, WebIDL::NotFoundError::create(realm, MUST(String::formatted("No data found for MIME type: {}", type))));
+
+    // 10. Return p.
+    return promise;
+}
+
+// https://w3c.github.io/clipboard-apis/#dom-clipboarditem-supports
+bool ClipboardItem::supports(JS::VM&, String const& type)
+{
+    // 1. If type is in mandatory data types or optional data types, then return true.
+    // 2. If not, then return false.
+    // TODO: Implement optional data types, like web custom formats and image/svg+xml.
+    return any_of(MANDATORY_DATA_TYPES, [&](auto supported) { return supported == type; });
+}
+
+ClipboardItem::ClipboardItem(JS::Realm& realm)
+    : Bindings::PlatformObject(realm)
+{
+}
+
+ClipboardItem::~ClipboardItem() = default;
+
+void ClipboardItem::initialize(JS::Realm& realm)
+{
+    Base::initialize(realm);
+    WEB_SET_PROTOTYPE_FOR_INTERFACE(ClipboardItem);
+}
+
+void ClipboardItem::visit_edges(Cell::Visitor& visitor)
+{
+    Base::visit_edges(visitor);
+    for (auto& representation : m_representations) {
+        visitor.visit(representation.data);
+    }
+}
+
+}
diff --git a/Libraries/LibWeb/Clipboard/ClipboardItem.h b/Libraries/LibWeb/Clipboard/ClipboardItem.h
new file mode 100644
index 00000000000..8e24942cab2
--- /dev/null
+++ b/Libraries/LibWeb/Clipboard/ClipboardItem.h
@@ -0,0 +1,64 @@
+/*
+ * Copyright (c) 2024, Feng Yu <f3n67u@outlook.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibGC/Ptr.h>
+#include <LibJS/Runtime/PromiseCapability.h>
+#include <LibWeb/Bindings/ClipboardItemPrototype.h>
+#include <LibWeb/DOM/Event.h>
+#include <LibWeb/Forward.h>
+#include <LibWeb/HTML/DataTransfer.h>
+#include <LibWeb/MimeSniff/MimeType.h>
+
+namespace Web::Clipboard {
+
+constexpr auto WEB_CUSTOM_FORMAT_PREFIX = "web "sv;
+
+inline constexpr Array MANDATORY_DATA_TYPES = {
+    "text/plain"sv, "text/html"sv, "image/png"sv
+};
+
+struct ClipboardItemOptions {
+    Bindings::PresentationStyle presentation_style { Bindings::PresentationStyle::Unspecified };
+};
+
+// https://w3c.github.io/clipboard-apis/#clipboard-item-interface
+class ClipboardItem : public Bindings::PlatformObject {
+    WEB_PLATFORM_OBJECT(ClipboardItem, Bindings::PlatformObject);
+    GC_DECLARE_ALLOCATOR(ClipboardItem);
+
+public:
+    struct Representation {
+        String mime_type;              // The MIME type (e.g., "text/plain").
+        bool is_custom;                // Whether this is a web custom format.
+        GC::Ref<WebIDL::Promise> data; // The actual data for this representation.
+    };
+
+    static WebIDL::ExceptionOr<GC::Ref<ClipboardItem>> construct_impl(JS::Realm&, OrderedHashMap<String, GC::Root<WebIDL::Promise>> const& items, ClipboardItemOptions const& options = {});
+
+    virtual ~ClipboardItem() override;
+
+    Bindings::PresentationStyle presentation_style() const { return m_presentation_style; }
+
+    Vector<String> const& types() const { return m_types; }
+
+    WebIDL::ExceptionOr<GC::Ref<WebIDL::Promise>> get_type(String const& type);
+
+    static bool supports(JS::VM&, String const& type);
+
+private:
+    ClipboardItem(JS::Realm&);
+
+    virtual void initialize(JS::Realm&) override;
+    virtual void visit_edges(Cell::Visitor&) override;
+
+    Bindings::PresentationStyle m_presentation_style;
+    Vector<String> m_types;
+    Vector<Representation> m_representations;
+};
+
+}
diff --git a/Libraries/LibWeb/Clipboard/ClipboardItem.idl b/Libraries/LibWeb/Clipboard/ClipboardItem.idl
new file mode 100644
index 00000000000..542b88e65b5
--- /dev/null
+++ b/Libraries/LibWeb/Clipboard/ClipboardItem.idl
@@ -0,0 +1,22 @@
+typedef Promise<(DOMString or Blob)> ClipboardItemData;
+
+// https://w3c.github.io/clipboard-apis/#clipboard-item-interface
+[SecureContext, Exposed=Window]
+interface ClipboardItem {
+    constructor(record<DOMString, ClipboardItemData> items,
+              optional ClipboardItemOptions options = {});
+
+    readonly attribute PresentationStyle presentationStyle;
+    // FIXME: Should be a FrozenArray<DOMString>
+    readonly attribute sequence<DOMString> types;
+
+    Promise<Blob> getType(DOMString type);
+
+    static boolean supports(DOMString type);
+};
+
+enum PresentationStyle { "unspecified", "inline", "attachment" };
+
+dictionary ClipboardItemOptions {
+    PresentationStyle presentationStyle = "unspecified";
+};
diff --git a/Libraries/LibWeb/Forward.h b/Libraries/LibWeb/Forward.h
index 1dbc892ad51..27d13ab4523 100644
--- a/Libraries/LibWeb/Forward.h
+++ b/Libraries/LibWeb/Forward.h
@@ -84,6 +84,7 @@ enum class XMLHttpRequestResponseType;
 
 namespace Web::Clipboard {
 class Clipboard;
+class ClipboardItem;
 }
 
 namespace Web::Compression {
diff --git a/Libraries/LibWeb/idl_files.cmake b/Libraries/LibWeb/idl_files.cmake
index 34dc23a850d..856c7f71fa4 100644
--- a/Libraries/LibWeb/idl_files.cmake
+++ b/Libraries/LibWeb/idl_files.cmake
@@ -9,6 +9,7 @@ libweb_js_bindings(Animations/DocumentTimeline)
 libweb_js_bindings(Animations/KeyframeEffect)
 libweb_js_bindings(Clipboard/Clipboard)
 libweb_js_bindings(Clipboard/ClipboardEvent)
+libweb_js_bindings(Clipboard/ClipboardItem)
 libweb_js_bindings(Compression/CompressionStream)
 libweb_js_bindings(Compression/DecompressionStream)
 libweb_js_bindings(Crypto/Crypto)
diff --git a/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp b/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
index 9c1629cd740..5bf2323dcb2 100644
--- a/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
+++ b/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
@@ -45,6 +45,7 @@ static bool is_platform_object(Type const& type)
         "CanvasGradient"sv,
         "CanvasPattern"sv,
         "CanvasRenderingContext2D"sv,
+        "ClipboardItem"sv,
         "CloseWatcher"sv,
         "CryptoKey"sv,
         "DataTransfer"sv,
@@ -247,6 +248,9 @@ CppType idl_type_name_to_cpp_type(Type const& type, Interface const& interface)
     if (type.name() == "Function")
         return { .name = "GC::Ref<WebIDL::CallbackType>", .sequence_storage_type = SequenceStorageType::MarkedVector };
 
+    if (type.name() == "Promise")
+        return { .name = "GC::Root<WebIDL::Promise>", .sequence_storage_type = SequenceStorageType::MarkedVector };
+
     if (type.name() == "sequence") {
         auto& parameterized_type = verify_cast<ParameterizedType>(type);
         auto& sequence_type = parameterized_type.parameters().first();
@@ -4663,6 +4667,7 @@ void generate_constructor_implementation(IDL::Interface const& interface, String
 #include <LibJS/Runtime/DataView.h>
 #include <LibJS/Runtime/GlobalObject.h>
 #include <LibJS/Runtime/Iterator.h>
+#include <LibJS/Runtime/PromiseConstructor.h>
 #include <LibJS/Runtime/ValueInlines.h>
 #include <LibJS/Runtime/TypedArray.h>
 #include <LibWeb/Bindings/@constructor_class@.h>
diff --git a/Tests/LibWeb/Text/expected/Clipboard/clipboarditem.txt b/Tests/LibWeb/Text/expected/Clipboard/clipboarditem.txt
new file mode 100644
index 00000000000..70dbc3c123c
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/Clipboard/clipboarditem.txt
@@ -0,0 +1,3 @@
+types: text/plain,text/uri-list
+getType('text/plain'): hello
+getType('text/uri-list'): https://example.com
diff --git a/Tests/LibWeb/Text/expected/all-window-properties.txt b/Tests/LibWeb/Text/expected/all-window-properties.txt
index 52d5ae7ddfb..a61ef9f9177 100644
--- a/Tests/LibWeb/Text/expected/all-window-properties.txt
+++ b/Tests/LibWeb/Text/expected/all-window-properties.txt
@@ -60,6 +60,7 @@ ChannelMergerNode
 CharacterData
 Clipboard
 ClipboardEvent
+ClipboardItem
 CloseEvent
 CloseWatcher
 Comment
diff --git a/Tests/LibWeb/Text/expected/wpt-import/clipboard-apis/clipboard-item.https.txt b/Tests/LibWeb/Text/expected/wpt-import/clipboard-apis/clipboard-item.https.txt
new file mode 100644
index 00000000000..b77aaa1e71b
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/wpt-import/clipboard-apis/clipboard-item.https.txt
@@ -0,0 +1,34 @@
+Harness status: OK
+
+Found 28 tests
+
+17 Pass
+11 Fail
+Fail	ClipboardItem({string, Blob}) succeeds with different types
+Pass	ClipboardItem() succeeds with empty options
+Pass	ClipboardItem({}) fails with empty dictionary input
+Pass	ClipboardItem(Blob) fails
+Pass	ClipboardItem() fails with null input
+Pass	ClipboardItem() fails with no input
+Fail	types() returns correct values
+Fail	getType(DOMString valid type) succeeds with correct output
+Fail	getType(DOMString invalid type) succeeds with correct output
+Fail	getType(DOMString type) rejects correctly when querying for missing type
+Fail	getType(DOMString valid type) converts DOMString to Blob
+Fail	getType(DOMString invalid type) converts DOMString to Blob
+Pass	supports(text/plain) returns true
+Pass	supports(text/html) returns true
+Pass	supports(image/png) returns true
+Fail	supports(text/uri-list) returns true
+Fail	supports(image/svg+xml) returns true
+Fail	supports(web foo/bar) returns true
+Fail	supports(web text/html) returns true
+Pass	supports(web ) returns false
+Pass	supports(web) returns false
+Pass	supports(web foo) returns false
+Pass	supports(foo/bar) returns false
+Pass	supports(weB text/html) returns false
+Pass	supports( web text/html) returns false
+Pass	supports(not a/real type) returns false
+Pass	supports() returns false
+Pass	supports( ) returns false
\ No newline at end of file
diff --git a/Tests/LibWeb/Text/input/Clipboard/clipboarditem.html b/Tests/LibWeb/Text/input/Clipboard/clipboarditem.html
new file mode 100644
index 00000000000..d4da5a61eab
--- /dev/null
+++ b/Tests/LibWeb/Text/input/Clipboard/clipboarditem.html
@@ -0,0 +1,20 @@
+<script src="../include.js"></script>
+<script type="text/javascript">
+    asyncTest(async (done) => {
+        const blob = new Blob(['https://example.com'], {type: 'text/uri-list'});
+
+        const item = new ClipboardItem({'text/plain': 'hello', 'text/uri-list': blob});
+
+        println(`types: ${item.types}`);
+
+        const blobOutput = await item.getType('text/plain');
+        const text = await (new Response(blobOutput)).text();
+        println(`getType('text/plain'): ${text}`);
+        
+        const blobOutput2 = await item.getType('text/uri-list');
+        const text2 = await (new Response(blobOutput2)).text();
+        println(`getType('text/uri-list'): ${text2}`);
+
+        done();
+    });
+</script>
diff --git a/Tests/LibWeb/Text/input/wpt-import/clipboard-apis/clipboard-item.https.html b/Tests/LibWeb/Text/input/wpt-import/clipboard-apis/clipboard-item.https.html
new file mode 100644
index 00000000000..5183e5e0c16
--- /dev/null
+++ b/Tests/LibWeb/Text/input/wpt-import/clipboard-apis/clipboard-item.https.html
@@ -0,0 +1,124 @@
+<!doctype html>
+<meta charset="utf-8">
+<title>ClipboardItem tests</title>
+<link rel="help" href="https://w3c.github.io/clipboard-apis/#async-clipboard-api">
+<script src="../resources/testharness.js"></script>
+<script src="../resources/testharnessreport.js"></script>
+<script>
+
+const blob = new Blob(['hello'], {type: 'text/plain'});
+const blob2 = new Blob(['this should work'], {type: 'not a/real type'});
+
+test(() => {
+  new ClipboardItem({'text/plain': blob});
+  new ClipboardItem({'text/plain': blob, 'not a/real type': blob2});
+}, "ClipboardItem({string, Blob}) succeeds with different types");
+
+test(() => {
+  new ClipboardItem({'text/plain': blob}, {});
+}, "ClipboardItem() succeeds with empty options");
+
+test(() => {
+  assert_throws_js(TypeError, () => {new ClipboardItem({});});
+}, "ClipboardItem({}) fails with empty dictionary input");
+
+test(() => {
+  assert_throws_js(TypeError, () => {new ClipboardItem(blob);});
+}, "ClipboardItem(Blob) fails");
+
+test(() => {
+  assert_throws_js(TypeError, () => {new ClipboardItem(null);});
+}, "ClipboardItem() fails with null input");
+
+test(() => {
+  assert_throws_js(TypeError, () => {new ClipboardItem();});
+}, "ClipboardItem() fails with no input");
+
+test(() => {
+  const item = new ClipboardItem({'text/plain': blob});
+  const types = item.types;
+  assert_equals(types.length, 1);
+  assert_equals(types[0], 'text/plain');
+  const item2 =
+      new ClipboardItem({'text/plain': blob, 'not a/real type': blob2});
+  const types2 = item2.types;
+  assert_equals(types2.length, 2);
+  assert_equals(types2[0], 'text/plain');
+  assert_equals(types2[1], 'not a/real type');
+}, "types() returns correct values");
+
+promise_test(async () => {
+  const item =
+      new ClipboardItem({'text/plain': blob, 'not a/real type': blob2});
+
+  const blobOutput = await item.getType('text/plain');
+  assert_true(blobOutput.type.includes('text/plain'));
+  const text = await (new Response(blobOutput)).text();
+
+  assert_equals('hello', text);
+}, "getType(DOMString valid type) succeeds with correct output");
+
+promise_test(async () => {
+  const item =
+      new ClipboardItem({'text/plain': blob, 'not a/real type': blob2});
+
+  const blobOutput = await item.getType('not a/real type');
+  assert_true(blobOutput.type.includes('not a/real type'));
+  const text = await (new Response(blobOutput)).text();
+
+  assert_equals('this should work', text);
+}, "getType(DOMString invalid type) succeeds with correct output");
+
+promise_test(async t => {
+  const item =
+      new ClipboardItem({'text/plain': blob, 'not a/real type': blob2});
+  promise_rejects_dom(t, "NotFoundError", item.getType('type not in item'));
+  promise_rejects_dom(t, "NotFoundError", item.getType('text/plain:subtype'));
+}, "getType(DOMString type) rejects correctly when querying for missing type");
+
+promise_test(async () => {
+  const item =
+      new ClipboardItem({'text/plain': 'abc', 'not a/real type': 'xxx'});
+  const blob = await item.getType('text/plain');
+  assert_equals(blob.type, 'text/plain');
+
+  const text = await (new Response(blob)).text();
+  assert_equals(text, 'abc');
+}, "getType(DOMString valid type) converts DOMString to Blob");
+
+promise_test(async () => {
+  const item =
+      new ClipboardItem({'text/plain': 'abc', 'not a/real type': 'xxx'});
+  const blob = await item.getType('not a/real type');
+  assert_equals(blob.type, 'not a/real type');
+
+  const text = await (new Response(blob)).text();
+  assert_equals(text, 'xxx');
+}, "getType(DOMString invalid type) converts DOMString to Blob");
+
+[
+  // mandatory data types
+  ['text/plain', true],
+  ['text/html',  true],
+  ['image/png',  true],
+  // optional data types
+  ['text/uri-list', true],
+  ['image/svg+xml', true],
+  ['web foo/bar',   true],
+  ['web text/html', true],
+  // invalid types
+  ['web ',            false],
+  ['web',             false],
+  ['web foo',         false],
+  ['foo/bar',         false],
+  ['weB text/html',   false],
+  [' web text/html',  false],
+  ['not a/real type', false],
+  ['',                false],
+  [' ',               false],
+].forEach(([type, result]) => {
+  promise_test(async () => {
+    assert_equals(ClipboardItem.supports(type), result);
+  }, `supports(${type}) returns ${result ? "true" : "false"}`);
+});
+</script>