UUID Generator
Generate random v4 UUIDs in bulk, with or without hyphens.
Identifiers you can trust
A UUID is a 128 bit identifier, usually written as 36 characters with four hyphens. Version 4 is random, which makes it safe to generate on any device without coordination.
These are produced with the browser’s cryptographic random source and the version bits are set correctly, so the output is a valid v4 UUID rather than a random string in the right shape.
How to use it
- Choose how many you need, up to 500.
- Toggle uppercase or remove hyphens if a system requires it.
- Generate and copy the list.
Where UUIDs help
- Database keys that do not reveal row counts or order.
- File names that will not collide between devices.
- Request ids for tracing a single operation through logs.
- Idempotency keys for payment and API requests.
- Test data that looks realistic.
A note on sortability
Random UUIDs do not sort by creation time. If you need ordered identifiers, use UUID v7 or a ULID, both of which embed a timestamp. Version 4 remains the right choice when ordering does not matter.
To generate a secret rather than an identifier, use Password Generator. To fingerprint a value, Hash Generator is the right tool.
Frequently asked
Are these UUIDs random enough?
Yes. They are generated with crypto.getRandomValues, the browser's cryptographic source, not a predictable pseudo random function.
What version are they?
Version 4, which is random. The version and variant bits are set correctly so the value is a valid RFC 4122 UUID.
Can I use them as database keys?
Yes, but consider the storage cost. A UUID is 16 bytes as binary, or 36 characters as text. For very large tables, a sortable identifier is often a better key.
Are duplicates possible?
In theory yes. In practice the space is so large that a collision is not a realistic concern for application use.