Developer · Free Tool
UUID Generator
Generate cryptographically random version-4 UUIDs — one or in bulk — and copy them instantly.
About this tool
Generate one or many version-4 UUIDs (universally unique identifiers) using the browser's cryptographically secure random number generator. Choose the quantity, generate, and copy individual IDs or the whole list.
A v4 UUID contains 122 bits of randomness, making collisions practically impossible — which is why UUIDs are the default choice for database primary keys, API request IDs, and distributed systems where IDs must be generated independently.
Common uses
- Generate primary keys or external IDs for database records
- Create correlation IDs for tracing requests across services
- Produce unique file or resource names that will never clash
Frequently asked questions
Can two generated UUIDs ever collide?
Theoretically yes, practically no. With 122 random bits you would need to generate about 2.7 quintillion UUIDs to reach even a 50% chance of one collision.
What do the 4 and the 8/9/a/b in a UUID mean?
The 4 marks the UUID version (random), and the following group's first character (8, 9, a, or b) encodes the variant. The rest is random data.
Is my data uploaded to a server?
No. This tool runs entirely in your browser using JavaScript — nothing you type is transmitted, logged, or stored anywhere. You can even use it offline once the page has loaded.