Private · on device. Runs in your browser: your file is not uploaded. No sign-up.
Made with your browser's secure random generator.
Choose the version and how many you need, then copy them or download a .txt file with one per line. Nothing is sent anywhere and there is no limit on how often you generate.
Random v4 keys scatter new rows across a database index, which slows inserts on large tables. v7 keys begin with a timestamp, so new keys land at the end of the index, like an auto-increment number, while still being unique across servers without coordination.
A v4 UUID is 122 random bits. A v7 UUID, defined in RFC 9562 (2024), starts with the time it was made in milliseconds followed by 74 random bits, so v7 IDs sort in the order they were created. That keeps database indexes compact and makes the IDs roughly chronological; v4 is the safe default when order does not matter.
In practice, no. With 122 random bits you would need to make about a billion v4 UUIDs a second for 85 years to have a 50% chance of a single repeat. v7 IDs made in the same millisecond still have 74 random bits each, and this tool gives each one in a batch its own millisecond so they stay in order.
They come from crypto.getRandomValues, the browser's cryptographically secure generator. But a UUID is an identifier, not a secret: a v7 UUID reveals when it was made. For passwords and keys, use the password generator.
Microsoft's name for the same thing. GUIDs are often written in capitals and inside braces, {1B4E28BA-2FA1-11D2-883F-0016D3CCA427}; switch on capitals and braces to match.
For a v7 UUID, yes: paste it under "Check a UUID" to see its version and the time stamped into it. Version 4 UUIDs carry no time.
