Random v4 and time-ordered v7 UUIDs, up to 1,000 at once, plus a validator
Runs in your browser. Nothing you type is sent anywhere. Updated on 24 Oct 2026.A UUID is a 128-bit identifier, random enough that two machines will not produce the same one. Version 4 is fully random; version 7 begins with a timestamp, so rows sort by creation time. Up to 1,000 at once, generated by your browser's own crypto.
Choose "v4 random" or "v7 time-ordered" under Type.
Enter how many you need in How many, up to 1,000.
Turn Uppercase, Hyphens or Braces on or off to match the format your code expects.
Click Generate, then Copy; for a list, the download icon saves it as a text file.
This UUID generator creates version 4 and version 7 UUIDs in your browser, from one to a thousand at a time. Choose uppercase, no hyphens or curly braces, then copy the list or download it as a text file. Paste any UUID into the checker to see whether it is valid, which version it is, and when it was made if the version records a time.
Developers use it to seed test data, to create primary keys for fixtures, to fill an idempotency key in an API request, or to give a new service, feature flag or registry entry a stable identifier. Version 7 suits database keys: it starts with a timestamp, so new rows sort by creation time and indexes stay compact.
Version 4 values come from crypto.randomUUID. Version 7 values follow RFC 9562: 48 bits of milliseconds, the version and variant bits, a counter and random bits from crypto.getRandomValues. Within the same millisecond the counter increases, so every UUID in a batch is larger than the one before, even when you generate a thousand at once.
Two alternatives are built in. A ULID is 26 characters of Crockford base32, a millisecond timestamp followed by 80 random bits, and sorts as text; the monotonic option keeps IDs from one millisecond in order. A nanoid is a short random string, 21 URL-safe characters by default, with your own length and alphabet and an estimate of the collision odds. The checker decodes a ULID's time as well as a UUID's.
Nothing is sent to a server and generated values are never stored; options are remembered on this device. A UUID is an identifier, not a secret, so do not use one as a password or an access token. Related tools: Password Generator, Hash Generator, Unix Timestamp Converter.
Version 4 is entirely random apart from the version and variant bits. Version 7 starts with the time in milliseconds, then adds random bits, so v7 UUIDs sort in the order they were created. Use v7 for database primary keys, v4 when the order must not reveal anything.
In practice, yes. A v4 UUID has 122 random bits; you would need to generate billions per second for many years before a collision became likely. Version 7 adds a millisecond timestamp and a counter, which makes a clash within one generator impossible.
Yes. GUID is Microsoft's name for the same 128-bit identifier. Windows tools usually print it in uppercase inside curly braces, which you can switch on with the Uppercase and Braces options.
A ULID suits database keys and logs that should sort by time as plain text, in 26 characters instead of 36. A nanoid suits short IDs in URLs or file names, where a timestamp is not wanted. Use a UUID when a schema, an API or a database column type expects one.
Paste it into the Check a UUID box. It shows whether the value is valid, the version and variant, and for versions 1, 6 and 7 the date and time it was created. The version is the first digit of the third group.
No. They are generated in your browser with its secure random number generator and are never sent or stored. Only your options, such as uppercase or the number to generate, are remembered on this device.
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Also works as: UUID v4 Generator.
In the collection Test Data Generators.