What is a Version 4 UUID?
A Version 4 Universally Unique Identifier (UUID) is a 128-bit number used to uniquely identify information in computer systems. Unlike other versions of UUIDs that rely on MAC addresses or time-based generation, v4 UUIDs are generated entirely from pseudo-random numbers. The format consists of 32 hexadecimal digits displayed in five groups separated by hyphens, in the form 8-4-4-4-12.
Why Developers Use UUIDs
- Database Primary Keys: Using UUIDs as primary keys instead of auto-incrementing integers makes database merging and sharding significantly easier, as you never have to worry about ID collisions across different tables or databases.
- Distributed Systems: In modern microservice architectures, different services can generate records independently without needing to coordinate with a central database to get the next available ID.
- Security: Auto-incrementing IDs can expose the size of your database or business metrics to competitors (e.g., if user ID 500 registers today and 550 registers tomorrow, they know you acquired 50 users). UUIDs mask this data completely.
How to Use Our Bulk UUID Generator
We built this tool to save developers time. If you need a single UUID to mock data in an API, simply click the copy icon next to the generated ID. If you are seeding a large database table or writing a complex test suite, use the bulk generation input to create up to 100 UUIDs instantly. You can then click "Copy All" to grab the entire batch formatted cleanly on separate lines, ready to be pasted into your code editor or SQL script.