What this tool does
A UUID is a 128-bit identifier built for systems that cannot coordinate a central counter. Version 4 is pure randomness. Version 7 embeds a millisecond timestamp, so IDs sort by creation time — friendlier to database indexes. Values come from the browser's crypto API and never leave your device.
How to use it
- Pick v4 for random IDs or v7 for time-sortable ones.
- Choose how many you need, up to 100.
- Copy the batch or download it as a text file.
Questions
v4 or v7: which should I use?
Use v4 for opaque session IDs and tokens. Use v7 for database primary keys: it stores the creation time in the first bits, so inserts stay index-friendly and you can sort by ID.
Are these UUIDs cryptographically secure?
Yes. They are generated with crypto.getRandomValues and follow RFC 9562 for v7 and RFC 4122 for v4.
Can I use them in production?
Yes. The formats are standard, collision odds are negligible, and no registration or attribution is required.