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UUID regex tester

Test UUIDs and GUIDs against a ready regex: any 8-4-4-4-12 hex value, v4, v7, any RFC 9562 version, GUIDs with braces or 32 digits without hyphens. Paste IDs one per line to see which match, with the version and variant of each, then copy the JavaScript regex or HTML pattern.

UUID and GUID regex patterns

A UUID is 32 hex digits in groups of 8-4-4-4-12. The 13th digit is the version and the 17th digit holds the variant, which is 8, 9, a or b for RFC 9562 UUIDs. Default v4 pattern: /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i. Every preset below is checked against its match and no-match samples.

Validating UUIDs in a form

<form action="https://splitforms.com/api/submit" method="POST">
  <input type="hidden" name="access_key" value="YOUR_KEY">

  <label for="order-id">Order ID (UUID)</label>
  <input id="order-id" name="order_id" type="text" pattern="[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-4[0-9a-fA-F]{3}-[89abAB][0-9a-fA-F]{3}-[0-9a-fA-F]{12}" title="UUID such as f47ac10b-58cc-4372-a567-0e02b2c3d479" spellcheck="false" autocomplete="off" required>

  <button type="submit">Send</button>
</form>

The pattern attribute blocks a submit until the field holds a v4 UUID. HTML anchors the whole value and has no case-insensitive flag, so the pattern lists both a-f and A-F. Add required to reject an empty value. The form posts to splitforms, so each submitted ID arrives in your inbox.

// Generate: built into browsers and Node.js 19+
const id = crypto.randomUUID(); // always a lowercase v4

// Check: trim, lowercase, then test
const UUID_V4 = /^[0-9a-f]{8}-[0-9a-f]{4}-4[0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/;

function parseUuid(input) {
  const value = String(input).trim().toLowerCase();
  return UUID_V4.test(value) ? value : null;
}

Browser checks are easy to skip, so test the value again on your server. Generate new IDs with crypto.randomUUID() instead of building them by hand. When you check an ID, trim it, lowercase it and then run the regex, so that uppercase GUIDs and lowercase UUIDs are stored the same way.

UUID regex FAQ