UUID Generator & Decoder
Generate random v4 or time-ordered v7 UUIDs, ULIDs and Nano IDs using your browser’s secure random generator, or paste one to decode its version and timestamp.
Frequently Asked Questions
Should I use UUID v4 or v7?
v4 is fully random. v7 (RFC 9562) starts with a millisecond timestamp, so values sort by creation time, which keeps database indexes compact. Use v7 for primary keys and v4 when you don't want the creation time to be visible.
Are these UUIDs secure and unique?
They use crypto.getRandomValues, the browser's cryptographically secure generator. A v4 UUID has 122 random bits, so a collision is practically impossible.
What is a ULID?
A 26-character, URL-safe, sortable identifier: a 48-bit millisecond timestamp plus 80 random bits, encoded in Crockford base32.
What is the difference between a UUID and a GUID?
Nothing in practice. GUID is Microsoft's name for the same 128-bit identifier, often shown uppercase or in braces.