About UUID Generator

Generate universally unique identifiers (UUIDs) instantly. UUIDs are 128-bit values that are guaranteed to be unique across all systems and time. Perfect for database IDs, API keys, and unique identifiers in your applications.

Frequently Asked Questions

What is a UUID?

UUID (Universally Unique Identifier) is a 128-bit value used to uniquely identify information. It's represented as 32 hexadecimal digits displayed in groups separated by hyphens: 8-4-4-4-12 (example: 123e4567-e89b-12d3-a456-426614174000).

What are the different UUID versions?

Version 1 uses timestamp and MAC address. Version 4 (most common) uses random numbers. Version 3 and 5 use namespace and name hashing. Version 2 is similar to v1 but includes local domain info. Version 4 is recommended for most applications.

Are UUIDs truly unique?

UUIDs are designed to be unique across space and time. Version 4 UUIDs have a collision probability so low (about 1 in 5.3 x 10^36) that they're considered practically unique. The chance of generating duplicates is negligible.

When should I use UUIDs?

Use UUIDs for database primary keys (especially in distributed systems), API tokens, session identifiers, file names, transaction IDs, and any case where you need guaranteed unique identifiers without central coordination.

UUID vs Auto-increment IDs: which is better?

Auto-increment IDs are smaller, faster, and sequential. UUIDs are globally unique, don't reveal information about record count, and work better in distributed systems or when merging databases. Choose based on your specific needs.

Are UUIDs secure for sensitive applications?

Version 4 UUIDs are cryptographically random and suitable for most security purposes. However, don't use UUIDs as sole authentication tokens. For high-security applications, consider additional cryptographic protection or specialized secure token generation.