Generated UUID
Batch Generate
Recent UUIDs
UUID history is a Pro feature
Upgrade to ProHow to Use This Tool
Choose a version
Select UUID v4 (random) or v1 (time-based).
Generate
Click Generate for a single UUID or use Batch Generate for multiple.
Customize and copy
Toggle uppercase and hyphens, then copy to clipboard.
Features
V1 & V4 Support
Generate time-based (v1) or cryptographically random (v4) UUIDs.
Batch Generation
Generate up to 100 UUIDs at once for bulk operations.
Format Options
Toggle between uppercase/lowercase and with/without hyphens.
History (Pro)
Pro users get persistent UUID history across sessions.
Frequently Asked Questions
What is a UUID?
A UUID (Universally Unique Identifier) is a 128-bit identifier that is virtually guaranteed to be unique across all systems without coordination. UUIDs are widely used as database primary keys, API identifiers, and distributed system IDs.
What is the difference between UUID v1 and v4?
UUID v4 is generated from random numbers and is the most common choice for general use. UUID v1 is based on the current timestamp and a node identifier, making it sortable by creation time but potentially exposing timing information.
Can UUIDs collide?
Theoretically yes, but the probability is astronomically low. For UUID v4, you would need to generate about 2.7 quintillion UUIDs to have a 50% chance of a single collision. In practice, collisions do not happen.
Should I use UUIDs as database primary keys?
UUIDs work well as primary keys in distributed systems where auto-incrementing IDs are impractical. The tradeoff is larger storage size (16 bytes vs 4-8 bytes for integers) and potential index fragmentation with random v4 UUIDs.