What Is a UUID? Generating and Using v4 Random Identifiers
A UUID (Universally Unique Identifier) is the standard way to generate unique IDs in distributed systems — you've seen it in nearly every server and database table.
What is a UUID
A UUID is a 128-bit identifier, standard text form 550e8400-e29b-41d4-a716-446655440000, split into five segments by hyphens.
Why UUID v4
- Random enough that collisions are vanishingly rare
- No central service needed — fits distributed systems
- Harder to enumerate/guess than auto-increment IDs
- Easy to merge multi-source data without conflicts
Generate online
FreeToolset's UUID generator can batch-generate up to 100 v4 IDs at once, locally — great for testing and system integration.
💡 When a primary key needs ordering, v4 isn't the best choice; consider a timestamp-prefixed variant.