diff --git a/Userland/Libraries/LibWeb/CMakeLists.txt b/Userland/Libraries/LibWeb/CMakeLists.txt
index fed29efe8e..be29c7b82a 100644
--- a/Userland/Libraries/LibWeb/CMakeLists.txt
+++ b/Userland/Libraries/LibWeb/CMakeLists.txt
@@ -270,6 +270,7 @@ set(SOURCES
     HighResolutionTime/CoarsenTime.cpp
     HighResolutionTime/Performance.cpp
     Infra/ByteSequences.cpp
+    Infra/JSON.cpp
     IntersectionObserver/IntersectionObserver.cpp
     Layout/BlockContainer.cpp
     Layout/BlockFormattingContext.cpp
diff --git a/Userland/Libraries/LibWeb/Infra/JSON.cpp b/Userland/Libraries/LibWeb/Infra/JSON.cpp
new file mode 100644
index 0000000000..279e667162
--- /dev/null
+++ b/Userland/Libraries/LibWeb/Infra/JSON.cpp
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2022, Linus Groh <linusg@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibJS/Runtime/AbstractOperations.h>
+#include <LibJS/Runtime/Value.h>
+#include <LibWeb/Infra/JSON.h>
+#include <LibWeb/WebIDL/ExceptionOr.h>
+
+namespace Web::Infra {
+
+// https://infra.spec.whatwg.org/#parse-a-json-string-to-a-javascript-value
+WebIDL::ExceptionOr<JS::Value> parse_json_string_to_javascript_value(JS::VM& vm, StringView string)
+{
+    auto& realm = *vm.current_realm();
+
+    // 1. Return ? Call(%JSON.parse%, undefined, « string »).
+    return TRY(JS::call(vm, realm.intrinsics().json_parse_function(), JS::js_undefined(), JS::js_string(vm, string)));
+}
+
+// https://infra.spec.whatwg.org/#parse-json-bytes-to-a-javascript-value
+WebIDL::ExceptionOr<JS::Value> parse_json_bytes_to_javascript_value(JS::VM& vm, ReadonlyBytes bytes)
+{
+    // 1. Let string be the result of running UTF-8 decode on bytes. [ENCODING]
+    auto string = StringView { bytes };
+
+    // 2. Return the result of parsing a JSON string to an Infra value given string.
+    return parse_json_string_to_javascript_value(vm, string);
+}
+
+// https://infra.spec.whatwg.org/#serialize-a-javascript-value-to-a-json-string
+WebIDL::ExceptionOr<String> serialize_javascript_value_to_json_string(JS::VM& vm, JS::Value value)
+{
+    auto& realm = *vm.current_realm();
+
+    // 1. Let result be ? Call(%JSON.stringify%, undefined, « value »).
+    auto result = TRY(JS::call(vm, realm.intrinsics().json_stringify_function(), JS::js_undefined(), value));
+
+    // 2. If result is undefined, then throw a TypeError.
+    if (result.is_undefined())
+        return WebIDL::SimpleException { WebIDL::SimpleExceptionType::TypeError, "Result of stringifying value must not be undefined"sv };
+
+    // 3. Assert: result is a string.
+    VERIFY(result.is_string());
+
+    // 4. Return result.
+    return result.as_string().string();
+}
+
+// https://infra.spec.whatwg.org/#serialize-a-javascript-value-to-json-bytes
+WebIDL::ExceptionOr<ByteBuffer> serialize_javascript_value_to_json_bytes(JS::VM& vm, JS::Value value)
+{
+    auto& realm = *vm.current_realm();
+    auto& global_object = realm.global_object();
+
+    // 1. Let string be the result of serializing a JavaScript value to a JSON string given value.
+    auto string = TRY(serialize_javascript_value_to_json_string(vm, value));
+
+    // 2. Return the result of running UTF-8 encode on string. [ENCODING]
+    return TRY_OR_RETURN_OOM(global_object, ByteBuffer::copy(string.bytes()));
+}
+
+}
diff --git a/Userland/Libraries/LibWeb/Infra/JSON.h b/Userland/Libraries/LibWeb/Infra/JSON.h
new file mode 100644
index 0000000000..a2d128238a
--- /dev/null
+++ b/Userland/Libraries/LibWeb/Infra/JSON.h
@@ -0,0 +1,20 @@
+/*
+ * Copyright (c) 2022, Linus Groh <linusg@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Forward.h>
+#include <LibJS/Forward.h>
+#include <LibWeb/Forward.h>
+
+namespace Web::Infra {
+
+WebIDL::ExceptionOr<JS::Value> parse_json_string_to_javascript_value(JS::VM&, StringView);
+WebIDL::ExceptionOr<JS::Value> parse_json_bytes_to_javascript_value(JS::VM&, ReadonlyBytes);
+WebIDL::ExceptionOr<String> serialize_javascript_value_to_json_string(JS::VM&, JS::Value);
+WebIDL::ExceptionOr<ByteBuffer> serialize_javascript_value_to_json_bytes(JS::VM&, JS::Value);
+
+}