UUID Generator
WEBGenerate version-4 UUIDs and unique identifiers in bulk.
What is the UUID Generator tool?
This UUID generator creates version-4 UUIDs — the same 128-bit identifiers Microsoft calls GUIDs — one at a time or in bulk, up to 20 per batch. Each identifier is built from 16 bytes drawn from your browser's cryptographically secure random source (crypto.getRandomValues), then formatted to RFC 4122: lowercase hex in the familiar 8-4-4-4-12 pattern with the version and variant bits set correctly, ready to paste into any codebase, database or config file.
Everything runs client-side. There is no server call, no account and no record of what you generate — the list exists only in your browser tab. Copy a single UUID with a tap, or use the copy-all button to grab the entire batch with one id per line, which is exactly what you want when seeding a database, filling test fixtures, labelling devices or handing correlation ids to a batch job. Compared with the ad-heavy single-purpose generator pages that dominate this search, it is a clean tool with no sign-up and no clutter.
A random UUID generator is only as good as its randomness: version-4 ids carry 122 random bits, so the odds of two ever colliding are negligible for any realistic workload — you can treat each one as globally unique. The tool is free with no quota, works on your phone, and the same generator ships inside the Carbide app for Android and iOS (coming soon), where it runs fully offline.
How to use the UUID Generator
- Set how many UUIDs you need — anywhere from 1 to 20 per batch.
- The list of random version-4 UUIDs generates instantly; no button to press.
- Tap any single UUID to copy just that one.
- Tap «Copy all» to copy the whole batch, one UUID per line.
- Generate again whenever you need a fresh set — every batch is new randomness.
Frequently asked questions
Are v4 UUIDs really unique — can they collide?
A version-4 UUID contains 122 bits of randomness, which means you would need to generate about 2.7 quintillion UUIDs before even a 50% chance of one duplicate. Uniqueness is probabilistic rather than guaranteed, but in practice every system in the world treats v4 UUIDs as unique — and with a cryptographically secure source like this one, that assumption is sound.
What is the difference between a UUID and a GUID?
Nothing structural — GUID (globally unique identifier) is simply Microsoft's name for the same 128-bit RFC 4122 identifier. A GUID generator and a UUID generator produce interchangeable values; .NET, SQL Server and the rest of the Microsoft ecosystem just spell it differently.
Why version 4 and not version 1?
Version-1 UUIDs embed a timestamp and historically the machine's MAC address, which leaks when and where an id was made. Version 4 is pure randomness — nothing about you or your device is encoded in it — which is why it is the default choice almost everywhere today.
Is the generator cryptographically random?
Yes. The 16 bytes behind each UUID come from crypto.getRandomValues, the browser's cryptographically secure random number generator — not Math.random(). That said, a UUID is an identifier, not a secret: for session tokens or API keys, use a purpose-built random token.
Are the UUIDs I generate sent or stored anywhere?
No. Generation happens entirely in your browser — there is no network request, no log and no storage. Close the tab and the list is gone.
Can I generate UUIDs offline?
Yes — once the page has loaded, generation needs no connection at all. The Carbide app for Android and iOS (coming soon) includes the same generator working fully offline.
Is it free, and how many can I generate?
Free, no sign-up, no quota. Each batch holds up to 20 UUIDs and you can regenerate as many batches as you like.
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