NOPPAW

UUID Generator

The UUID Generator mints random version 4 UUIDs — the 36-character identifiers like 9b2f2079-3b7d-4e1f-a512-8c5d2e9a4471 that databases and APIs use as unguessable primary keys. Generation uses crypto.randomUUID where available and falls back to crypto.getRandomValues, so every UUID is built from cryptographic randomness. Make one, or make five hundred, with options for uppercase and hyphen-free output.

How to use UUID Generator

  1. Set how many UUIDs you need.
  2. Choose uppercase if your system shouts its identifiers, and hyphens on or off.
  3. Press Generate, then copy or download the list.

Supported behavior

  • Every UUID is version 4: the version nibble is always 4 and the variant bits are always 8, 9, a or b.
  • Bulk generation up to 1,000 UUIDs per click stays instant because it is all local.
  • Hyphen-free mode outputs the compact 32-hex-character form some APIs prefer.

Best for

  • Database primary keys and seed data.
  • Test fixtures, idempotency keys and correlation IDs.
  • File renaming batches that must never collide.

Limits

  • UUIDs are random, not sequential — if your database indexes suffer from random inserts, that is a storage-engine trade-off to weigh, not a flaw in the IDs.
  • A v4 UUID carries 122 bits of randomness; collisions are a practical impossibility, but no tool can prove a negative — critical systems still enforce uniqueness constraints.

Privacy notes

  • UUIDs are generated with your browser's cryptographic random source and never leave your device.
  • Nothing you generate is recorded, counted or stored by the page.

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UUID Generator FAQ

What makes a UUID 'version 4'?

Version 4 means the UUID is built from random bits (except the fixed version and variant markers). You can recognize one by the '4' at the start of the third group and an 8, 9, a or b at the start of the fourth.

Are UUID and GUID the same thing?

Effectively yes — GUID is Microsoft's name for the same 128-bit identifier format. A v4 UUID from this tool works anywhere a random GUID is expected.

Can two generated UUIDs ever collide?

With 122 random bits, you would need to generate billions before a collision became remotely plausible. For everyday use, treat them as unique — and keep database uniqueness constraints as a backstop.