JavaScript RegExp Unicode Escape Metacharacter (\uXXXX)

What Is \uXXXX?

\uXXXX matches one character by its Unicode code unit: the letter u plus exactly four hex digits (0–9, A–F). Example: \u0041 is the letter A.

\u0041 → "A"     (U+0041)
\u00A9 → "©"     (U+00A9)
\u2665 → "♥"     (U+2665)

/\u0041/.test("A")     → true
/\u0041/.test("B")     → false
/\u00A9/.test("© 2026") → true

How to Use \uXXXX

Look up the code point, write four hex digits, then test or replace.

1. Find the character’s code (for example U+00A9 for ©).
2. Write \u plus four hex digits: \u00A9.
3. Use it in a pattern: /\u00A9/, or in a string: "\u00A9".
4. Add flags like i or g when case or global replace matters.

Pseudocode

pattern has "\u" + fourHexDigits
target = codeUnitFromHex(fourHexDigits)   // 0 … 65535

read next character ch from the string
if ch.codeUnit === target:
    accept match
else:
    fail this path

examples:
  \u0041 → match "A"
  \u00A9 → match "©"
  \u2665 → match "♥"

Cheat Sheet

Handy codes and rules for everyday Unicode escapes.

Live Preview

Run common \uXXXX checks against letters and symbols.

text = "A"
/\u0041/.test(text)
→ true

/* U+0041 is the letter A */

JavaScript Examples

Short, copy-ready snippets. Open DevTools Console, or use Try It Yourself for a live editor.

console.log(/\u0041/.test("A"));     // true
console.log(/\u0041/.test("B"));     // false
console.log(/\u0041/.test("Apple")); // true

true
false
true

console.log(/\u00A9/.test("© 2026")); // true
console.log(/\u2665/.test("I ♥ JS")); // true
console.log(/\u00A9/.test("(c)"));    // false

true
true
false

const text = "©";

console.log(/\u00A9/.test(text)); // true
console.log(/\xA9/.test(text));   // true
console.log("\u00A9" === "\xA9"); // true

true
true
true

Performance Notes

Escapes compile to ordinary character matches—no special runtime cost. Prefer \xHH only when you intentionally stay in the 0–255 byte range.

Key Takeaways