Developer ToolsGeneratorsFree Tool
UUID Generator v4
Generate a random RFC 4122 version 4 UUID with the version and variant bits set correctly.
How to Use UUID Generator v4
- 1Click Process to generate a new UUID v4
- 2Copy the result
- 3Click Process again for another random UUID
Frequently Asked Questions
Each hex digit is randomly generated, and the version (4) and variant bits are set correctly per RFC 4122 — giving the standard UUID v4 shape with effectively no collision risk in practice.
Yes for most purposes — UUID v4 is widely used as a primary key format. If you specifically need cryptographically unpredictable IDs for security purposes (like session tokens), the API Key/Token Generator uses crypto.getRandomValues rather than Math.random.
v4 is fully random; v1 (a separate tool on this site) encodes the current timestamp plus a random node identifier, making it roughly sortable by creation time but revealing when it was generated.
No — generation happens entirely in your browser.
Related Tools
UUID Generator v1
Generate a real RFC 4122 version 1 (time-based) UUID, encoding the current timestamp plus a randomly-generated node identifier.
NanoID Generator
Generate a cryptographically random, URL-friendly ID using the same 21-character length and default alphabet as the popular nanoid library.
ULID Generator
Generate a real, spec-compliant ULID — a 26-character, lexicographically sortable ID with a Crockford base32-encoded timestamp and random suffix.
CUID Generator
Generate a CUID-style ID — a 'c' prefix, base36 timestamp, and cryptographically random suffix — a simplified approximation, not the exact CUID2 reference algorithm.