Instantly Generate Cryptographically Secure UUIDs
Whether you are seeding a database, creating unique session tokens, or building a distributed system, you often need a reliable UUID (or GUID) generator. Our tool operates entirely in your browser, ensuring that your generated IDs are fast, private, and secure.
Using the modern Web Crypto API, it generates true Version 4 UUIDs that are guaranteed to be random. You can easily toggle uppercase formatting or remove hyphens to match your exact data requirements.
UUID Structure and Collision Probability
| Feature | Details |
|---|---|
| Format | 8-4-4-4-12 (32 hex digits + 4 hyphens) |
| Possible Values | 3.4 × 1038 (2122) |
| Collision Chance | Effectively zero |
| Generation Method | Cryptographically Secure PRNG |
Best Practices for Using UUIDs
- Database Keys: UUIDs are great for distributed databases or microservices since they can be generated independently without central coordination.
- Index Performance: If you are using UUIDs as primary keys in a relational database (like PostgreSQL or MySQL), be aware that their randomness can cause index fragmentation. Consider storing them in binary format.
- Security: Always use a v4 UUID for tokens or session IDs, as v1 UUIDs expose the MAC address and timestamp of the generating machine.