UUID v4 Generator
Generate universally unique identifiers instantly and securely. 100% in your browser, no data sent to any server.
UUID v4 Examples
| Generated UUID v4 | Common Use |
|---|---|
| 550e8400-e29b-41d4-a716-446655440000 | Primary key in a database |
| 6ba7b810-9dad-11d1-80b4-00c04fd430c8 | User session identifier |
| f47ac10b-58cc-4372-a567-0e02b2c3d479 | API authentication token |
| a0eebc99-9c0b-4ef8-bb6d-6bb9bd380a11 | File ID in a storage system |
| c73bcdcc-2669-4bf6-81d3-e4ae73fb11fd | Transaction ID in a payment system |
| 8a6e0804-d76d-4927-b91d-9d4a35b3c987 | Message ID in an event queue (e.g. Kafka) |
Frequently Asked Questions
What is a UUID v4?
A UUID v4 is a randomly generated universally unique identifier made up of 32 hexadecimal characters in the format xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx. Defined by RFC 4122, it guarantees uniqueness without coordination between systems.
What is a UUID used for?
UUIDs are used as primary keys in databases, session identifiers, authentication tokens, file IDs, and in distributed systems where multiple servers need to generate IDs without conflicts.
Is a UUID v4 safe to use in production?
Yes. Our generator uses the Web Crypto API (crypto.getRandomValues()), which is cryptographically secure. The probability of generating two identical UUIDs is astronomically low — approximately 1 in 5.3 x 10^36.
What is the difference between UUID v1 and UUID v4?
UUID v1 is generated based on the device MAC address and current time, which can expose system information. UUID v4 is completely random, making it more secure and suitable for most modern applications.
Can I use these UUIDs as primary keys in a database?
Yes. UUID v4s are widely used as primary keys in PostgreSQL, MySQL, and MongoDB. The main advantage is being able to generate the ID on the client or across distributed servers without collision risk.
Are the generated UUIDs stored or sent to any server?
No. Everything runs exclusively in your browser using JavaScript. No generated UUID is transmitted, logged, or stored by Raem Labs OÜ.