Developer Tools5 min read•2026-05-30
UUID Generator Free: Generate Unique IDs Online
By FreeToolbox Team
UUID Generator Free: Generate Unique IDs Online
Need unique identifiers? Our free UUID generator creates RFC 4122 compliant UUIDs instantly.
What is a UUID?
UUID (Universally Unique Identifier) is a 128-bit identifier guaranteed to be unique. Also known as GUID (Globally Unique Identifier).
Example: 550e8400-e29b-41d4-a716-446655440000
UUID Versions
| Version | Format | Use Case |
|---|---|---|
| v1 | Time + MAC | Time-based ordering |
| v3 | Name-based MD5 | Deterministic |
| v4 | Random | General purpose (most common) |
| v5 | Name-based SHA1 | Deterministic, secure |
Why Use UUIDs?
- Database primary keys (no coordination needed)
- Distributed systems
- API resource identifiers
- Session tokens
- File naming
FreeToolbox UUID Generator
Features: - 100% free, no registration - UUIDv4 generation - Bulk generation (up to 100) - Uppercase/lowercase toggle - One-click copy
Try: [UUID Generator](/tools/uuid-generator)
UUID vs Auto-Increment
| Feature | UUID | Auto-Increment |
|---|---|---|
| Global uniqueness | Yes | No |
| Speed | Fast | Very fast |
| Orderable | No (v4) | Yes |
| Size | 128 bits | 32/64 bits |
| Distributed | Easy | Difficult |
How to Use
- Choose format (hyphenated or compact)
- Select case
- Choose quantity (1-100)
- Generate and copy
Frequently Asked Questions
**Q: Are UUIDv4 truly random?** A: Yes, 122 random bits give 5.3 x 10^36 possibilities.
**Q: What is the difference between UUID and GUID?** A: Same thing. GUID is Microsoft's terminology.
[UUID Generator](/tools/uuid-generator)