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How do I check whether a string is a valid UUID?

Short answer

Paste the string into a browser-based UUID validator and it tells you whether the value is a valid UUID and, if so, which version and variant it is. The check runs on your device with no account needed.

A valid UUID has a strict format

A UUID is 32 hexadecimal digits arranged in five groups separated by hyphens, and certain positions encode its version and variant. A string that is the wrong length, has stray characters, or has invalid version bits is not a real UUID even if it looks close. A validator parses the string against these rules and reports whether it passes.

See the version and variant too

Beyond a simple pass or fail, a good validator tells you which version the UUID is, from 1 through 8, and which variant, which is useful when debugging why one system rejects an id another accepts. The check happens in your browser, so the value you paste is never uploaded. It is free and needs no sign-up.

Step by step

  1. Open the validator. Open the UUID validator in your browser.
  2. Paste the string. Paste the value you want to check.
  3. Read the result. See whether it is valid and, if so, its version and variant.

Frequently asked questions

What makes a UUID valid?

It must be 32 hex digits in five hyphen-separated groups with valid version and variant bits.

Does it tell me the version?

Yes. A valid UUID is reported with its version number and variant.

Is the string I paste uploaded?

No. The check runs in your browser, so nothing is sent to a server.

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