A UUID generator is a free online tool that creates random version 4 universally unique identifiers, the 36-character IDs used as database keys, API tokens, and file names. Generate one or up to 100 at a time using your browser cryptographically secure random number generator, then copy them all or download as a text file.
How do I generate a UUID online?
Choose how many you need (1 to 100) and press Generate. Each version 4 UUID appears on its own line. Press Copy all to grab the list, or Download .txt to save it as a file.
Version 4 UUIDs are randomly generated 128-bit values, formatted as 32 hex digits in five groups (8-4-4-4-12), for example 123e4567-e89b-12d3-a456-426614174000. The version and variant bits are set per RFC 4122 so other systems recognize the format.
Are these UUIDs safe to use as database keys?
Yes. They are generated with crypto.getRandomValues, a cryptographically secure source, and the chance of two v4 UUIDs colliding is negligible for any realistic workload. They work as primary keys, idempotency keys, file names, and tokens.
If you need time-ordered IDs for database index performance, consider UUID v7 instead. For pure uniqueness, v4 is the standard choice, and generating them client-side keeps your keys out of server logs.
Frequently asked questions
Is this UUID generator free?
Yes. Generate unlimited UUIDs with no account and no limits. It runs entirely in your browser.
What UUID version is generated?
Version 4 (random). The version digit is fixed to 4 and the variant bits are set correctly per RFC 4122.
How random are the UUIDs?
They use crypto.getRandomValues, the browser cryptographically secure random generator, which is far stronger than Math.random and suitable for tokens and keys.
Can two UUIDs ever be the same?
Theoretically yes, practically never: with 122 random bits, you would need to generate billions per second for a century before a collision became likely.
What is the difference between UUID and GUID?
Almost nothing. GUID is Microsoft term for the same 128-bit identifier format; a v4 UUID is a valid GUID.