About UUID Generator
UUID generator creates globally unique identifiers (UUID v1/v4/v5) online with batch generation, case conversion, formatting. Essential for database primary keys, distributed IDs, API request IDs.
How to Use
- Choose UUID version (v1/v4/v5)
- Set generation count
- Click generate
- Copy UUID or batch download
Frequently Asked Questions
- UUID v1 vs v4 difference?
- v1 based on timestamp+MAC address, theoretically traceable to device/time but may leak privacy. v4 fully random, better security, mainstream choice. v5 based on namespace+name hash.
- Can UUIDs collide?
- Theoretically yes but extremely unlikely. UUID v4 has 2^122 possibilities, generating 1 billion UUIDs has ~10^-18 collision probability. Practically considered collision-free.
- Can UUID be database primary key?
- Yes but with cost. UUID takes space (36 chars or 16 bytes), unordered causes poor index performance. For high concurrency, suggest ordered distributed IDs like Snowflake.