UUID
Generate v1 / v4 UUIDs.
A free UUID / ULID generator supporting UUID v4, v7, ULID and nil, with several output formats and batch generation. Every ID is created locally using the browser’s cryptographic random source.
How to use
- Pick a version: v4, v7, ULID or nil.
- Set how many to generate with the slider (nil is always one).
- Choose a format such as standard, no-hyphen, uppercase, {braces} or urn:uuid:.
- Click Generate to refresh, or Copy all to grab the whole batch.
FAQ
- What’s the difference between UUID v4 and v7?
- v4 is fully random; v7 embeds a millisecond timestamp in its prefix so the IDs sort by creation time, which is friendlier for database primary keys.
- What is a ULID?
- A ULID is a 26-character, Crockford Base32 identifier that’s also time-sortable, more compact than a UUID and URL-friendly.
- Are the IDs random and unique enough?
- Yes. The random bits come from the browser’s cryptographically secure RNG (CSPRNG); collisions are negligible in practice, and everything is generated locally.
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