diff --git a/Tests/LibWeb/CMakeLists.txt b/Tests/LibWeb/CMakeLists.txt
index 61a6aeb353..7bfd1699fc 100644
--- a/Tests/LibWeb/CMakeLists.txt
+++ b/Tests/LibWeb/CMakeLists.txt
@@ -1,4 +1,5 @@
 set(TEST_SOURCES
+    TestCSSIDSpeed.cpp
     TestHTMLTokenizer.cpp
 )
 
diff --git a/Tests/LibWeb/TestCSSIDSpeed.cpp b/Tests/LibWeb/TestCSSIDSpeed.cpp
new file mode 100644
index 0000000000..e42e7da8f7
--- /dev/null
+++ b/Tests/LibWeb/TestCSSIDSpeed.cpp
@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2023, Ben Wiederhake <BenWiederhake.GitHub@gmx.de>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibTest/TestCase.h>
+
+#include <LibWeb/CSS/ValueID.h>
+
+TEST_CASE(basic)
+{
+    EXPECT_EQ(Web::CSS::value_id_from_string("italic"sv), Web::CSS::ValueID::Italic);
+    EXPECT_EQ(Web::CSS::value_id_from_string("inline"sv), Web::CSS::ValueID::Inline);
+    EXPECT_EQ(Web::CSS::value_id_from_string("small"sv), Web::CSS::ValueID::Small);
+    EXPECT_EQ(Web::CSS::value_id_from_string("smalL"sv), Web::CSS::ValueID::Small);
+    EXPECT_EQ(Web::CSS::value_id_from_string("SMALL"sv), Web::CSS::ValueID::Small);
+    EXPECT_EQ(Web::CSS::value_id_from_string("Small"sv), Web::CSS::ValueID::Small);
+    EXPECT_EQ(Web::CSS::value_id_from_string("smALl"sv), Web::CSS::ValueID::Small);
+}
+
+BENCHMARK_CASE(value_id_from_string)
+{
+    for (size_t i = 0; i < 10'000'000; ++i) {
+        EXPECT_EQ(Web::CSS::value_id_from_string("inline"sv), Web::CSS::ValueID::Inline);
+    }
+}