Developer & Web Tools
UUID Generator
Generate cryptographically random version 4 UUIDs, singly or in bulk.
Privacy
Everything on this page runs inside your browser. Nothing you paste, type or upload is transmitted, logged or stored.
Tips
- Version 4 UUIDs carry 122 random bits. You would need to generate about 2.7 × 10¹⁸ of them before a collision became likely.
- They are random, so they make poor primary keys in large tables — the index fragments. UUIDv7 or an auto-increment column indexes far better.
- The version 4 marker is fixed: the 13th hex digit is always 4, and the 17th is 8, 9, a or b.
Frequently asked questions
Are these safe to use as security tokens?
They are generated with the browser’s cryptographic random source, so the entropy is sound. Even so, use a purpose-built token with an expiry and server-side validation for sessions or password resets.