diff --git a/package.json b/package.json
index 61be3ef..5ebe8df 100644
--- a/package.json
+++ b/package.json
@@ -26,9 +26,6 @@
 		"typedoc-material-theme": "^1.3.0"
 	},
 	"pnpm": {
-		"onlyBuiltDependencies": [
-			"@biomejs/biome",
-			"esbuild"
-		]
+		"onlyBuiltDependencies": ["@biomejs/biome", "esbuild"]
 	}
 }
diff --git a/src/ts/strings.test.ts b/src/ts/strings.test.ts
index 318605a..fc59197 100644
--- a/src/ts/strings.test.ts
+++ b/src/ts/strings.test.ts
@@ -14,3 +14,14 @@ describe('endsWithOneOf', () => {
 		expect(strings.endsWithOneOf('baa', ['ab', 'ac'])).toBe(false);
 	});
 });
+
+describe('iEqual', () => {
+	it('returns true when strings are equal', () => {
+		expect(strings.iEqual('A', 'a')).toBe(true);
+		expect(strings.iEqual('Hello, World!', 'hello, world!')).toBe(true);
+	});
+
+	it('returns false when strings are not equal', () => {
+		expect(strings.iEqual('a', 'b')).toBe(false);
+	});
+});
diff --git a/src/ts/strings.ts b/src/ts/strings.ts
index ef680c1..1a00e51 100644
--- a/src/ts/strings.ts
+++ b/src/ts/strings.ts
@@ -37,3 +37,18 @@ export function endsWithOneOf(str: string, strings: string[]): boolean {
 
 	return false;
 }
+
+/** Case insensitive equality. Returns true if `left.toLowerCase()` and `right.toLowerCase()` are equal.
+ *
+ * @param left
+ * @param right
+ * @returns
+ *
+ * ## Usage
+ * ```ts
+ * iEqual('Hello, World!', 'hello, World!'); // true
+ * ```
+ */
+export function iEqual(left: string, right: string): boolean {
+	return left.toLowerCase() === right.toLowerCase();
+}