DevPocket
UUID generator
A UUID is a 128-bit identifier that is practically impossible to repeat, useful as a database key, file name or request ID. This tool generates up to 1000 at once with the browser’s cryptographic generator (Web Crypto).
Whatever you paste into DevPocket is processed in your browser and is neither stored nor sent.
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You can choose UUID v4, fully random, or v7, which starts with a timestamp and therefore sorts by creation time, which improves database index performance. You can also validate a UUID and see its version, variant and, for v7, the time it was created.
How to use it
- Choose the version (v4 or v7) and the count.
- Adjust the format: uppercase, hyphens or braces.
- Copy the UUIDs or paste an existing one to validate it.
Frequently asked questions
Can two UUID v4 values repeat?
In theory yes, but the probability is negligible: you would need to generate billions per second for decades to have a real chance of a collision.
When should I use v7 instead of v4?
When the identifier is a primary key in a database. Because they sort by time, v7 values cause less index fragmentation than random v4 values.
Limitations
- Regular expressions use the JavaScript engine; syntax may differ from PCRE, Python or Java.
- The text diff is designed for documents up to about 2 MB.