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UUID Generator
A version 4 UUID is 122 random bits written as 36 characters, unique enough that two generators anywhere can use it without coordination. Generate up to 500 at once in the format your system expects.
How to use it
- Choose how many you need.
- Pick lowercase, uppercase, braced or hyphen-free formatting.
- Generate and copy the whole block.
Examples
- Seeding a test database with 200 distinct identifiers.
- Braced uppercase for systems that follow the Microsoft GUID convention.
- The hyphen-free form for URL segments and file names.
Questions people ask
Are these random enough to rely on?
Yes. They come from the browser's cryptographic random generator, not from a simple pseudo-random function. The chance of a collision is so small that generating billions of them still leaves it negligible.
What makes version 4 different from version 7?
Version 4 is fully random, so consecutive values are unordered — which fragments database indexes. Version 7 puts a timestamp at the front so identifiers sort by creation time, which is now the preferred choice for primary keys.
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Updated: 2026-08-07