UUID Generator
A UUID (Universally Unique Identifier) is a 128-bit value used to identify records, sessions, or objects without a central authority handing out IDs. This tool generates both version 4 (fully random) and version 7 (time-ordered) UUIDs instantly, one or many at a time, entirely in your browser.
How to use
- Pick a version — v4 for fully random IDs, v7 for time-ordered IDs.
- Pick how many UUIDs you need (1–100) and click Generate.
- Optionally switch to uppercase or strip the hyphens.
- Copy a single UUID, or copy the whole list at once.
- Nothing is sent anywhere — generation uses your browser's built-in crypto API.
FAQ
What's the difference between v4 and v7?
Version 4 UUIDs are generated from random numbers with no inherent order. Version 7 (RFC 9562) embeds a millisecond Unix timestamp in the first 48 bits, so IDs sort chronologically — useful as database primary keys, since it avoids the index fragmentation that fully random v4 keys cause on insert.
Are these UUIDs cryptographically secure?
Yes — generated with the browser's Web Crypto API (crypto.randomUUID / crypto.getRandomValues), the same source used for cryptographic keys, not Math.random(). For v7, only the random portion needs this; the timestamp portion is public by design.
Can I use these as database primary keys?
Yes — v7 in particular is increasingly recommended for this, since its time-ordering keeps B-tree indexes append-mostly, unlike fully random v4 keys which scatter inserts across the index.