Can two generated UUIDs collide?

The probability is astronomically low for UUID v4 — practically safe to treat as unique for any real-world dataset size.

Are these cryptographically random?

Yes, when available the browser's crypto.randomUUID is used; only very old browsers fall back to a weaker method.

Can I use these as primary keys?

Yes, though be aware random UUIDs are not sequential, which can affect insert performance on very large indexed tables.

UUID Generator

Choose how many UUIDs you need and whether to use uppercase letters or hyphens, then generate a batch of random v4 identifiers instantly. Useful for database keys, test fixtures, and API request IDs.

Count:

Uppercase

Include hyphens

UUID v4 is randomly generated with an extremely low collision probability. Used for database IDs, session tokens, etc.

How to use

Set the quantity and letter-case options.
Click generate to produce a batch of UUID v4 identifiers.
Copy one identifier or all of them at once.

Frequently asked questions

Can two generated UUIDs collide?: The probability is astronomically low for UUID v4 — practically safe to treat as unique for any real-world dataset size.
Are these cryptographically random?: Yes, when available the browser's crypto.randomUUID is used; only very old browsers fall back to a weaker method.
Can I use these as primary keys?: Yes, though be aware random UUIDs are not sequential, which can affect insert performance on very large indexed tables.

Privacy

Every UUID is generated locally in your browser and never sent to a server.

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