UUID Generator
UUID Generator
Generate random version-4 UUIDs in bulk, and validate any UUID in the checker below.
The UUID Generator creates universally unique identifiers, the 128-bit codes that databases, APIs, and distributed systems use as IDs that never collide in practice. Generate one, five, or up to a hundred version-4 UUIDs at a time, in your choice of uppercase or lowercase, with or without hyphens, then copy them all in one click for seeding databases, test fixtures, or request tracing.
Randomness comes from your browser's cryptographic generator, through crypto.randomUUID where available and a standards-faithful getRandomValues fallback elsewhere. Version-4 UUIDs are built from random bits with the version and variant fields set correctly, which is why the third group always begins with 4 and the fourth group begins with 8, 9, A, or B.
The built-in validator checks any UUID you paste: it confirms the shape, then reads out the version number and variant from the relevant digits, which is exactly what you need when auditing IDs produced by another system. Everything runs in your browser; the IDs are generated on your device and never uploaded or stored.
How to use
- Set how many UUIDs you need, up to 100.
- Choose uppercase and hyphen options if your system needs them.
- Click Generate UUIDs, then Copy All.
- To check an existing ID, paste it into the validator and click Validate UUID.
Frequently asked questions
Can two generated UUIDs ever match?
In practice, no. Version-4 UUIDs carry 122 random bits, so accidental collisions are astronomically unlikely, which is precisely why systems worldwide use them as primary keys without a central counter.
What do the version and variant mean?
The version says how the UUID was made; 4 means random. The variant identifies the layout family, normally the RFC 4122 variant. The validator reads both from fixed positions inside the UUID itself.
Should I remove the hyphens?
Only if the receiving system asks for it. Hyphens are part of the standard text form; some databases and older tools prefer the compact 32-character version.
Are the UUIDs generated on a server?
No. They are generated locally with your browser's cryptographic random source.
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