UUIDs are the standard way to give records, files and sessions a unique ID without a central counter. This generator creates random version 4 UUIDs in your browser using the cryptographic random source built into modern browsers, falling back to a manual v4 builder on older ones. Make a single ID or a batch of up to 100, format them the way your system expects, and copy or download the list.
Formatting Options
UUIDs appear in several house styles, so the generator lets you switch the details: uppercase or lowercase letters, and hyphens included or stripped for databases that store the compact 32-character form. Bulk generation produces one UUID per line, ready to paste into seed files, fixtures or spreadsheets. Because generation uses crypto-grade randomness, collisions are practically impossible for any realistic batch size.
How to Generate UUIDs
- Set how many UUIDs you need, from 1 to 100.
- Choose uppercase if your system requires it.
- Toggle hyphens on or off.
- Click generate and review the list.
- Copy all of them at once, or download them as a text file.
Where UUIDs Get Used
Developers seed databases, name uploaded files so they never clash, and tag API requests for tracing. Testers fill forms that demand unique emails or reference numbers. System administrators label virtual machines and containers. Having a fast generator bookmarked saves the trip to a command line every time a fresh ID is needed.
Frequently Asked Questions
Are these real version 4 UUIDs?
Yes. The version nibble is 4 and the variant bits follow the RFC, and the random bits come from your browser's cryptographic generator where available.
Can two generated UUIDs ever match?
In theory any random system can collide, but with 122 random bits the chance is astronomically small — far lower than everyday risks like a disk failure.
Do the UUIDs leave my device?
No. Generation happens entirely in your browser; nothing is logged or sent anywhere.