UUID Validator

About this tool

Check whether a string is a valid UUID and identify its version (1-5) per RFC 4122.

Example

Input: 9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d

Output: Valid UUID, version 4

Privacy

This tool runs entirely in your browser. Your data is processed locally and never uploaded to a server.

How to use this tool

1. Paste a UUID string into the input field.
2. Click the validate button or run the check.
3. Read whether the value is valid under RFC 4122.
4. If it is valid, note the detected UUID version from 1 to 5.

Step by step, what happens

1. The tool first reads the full string exactly as you entered it, including hyphens and letter case.
2. It checks the UUID structure against RFC 4122, looking for the expected 8-4-4-4-12 character pattern and allowed hexadecimal characters.
3. If the format matches, it inspects the version field to identify whether the UUID is version 1, 2, 3, 4, or 5.
4. The result shows both validity and version so you can quickly confirm whether the string is a proper UUID.

Worked example

Suppose you want to check a common version 4 UUID copied from an API response.

Input: 550e8400-e29b-41d4-a716-446655440000

1. Paste the UUID into the validator and run the check.
2. The tool confirms that the string follows the RFC 4122 UUID format.
3. It detects the version from the version nibble and reports version 4.

Tips and common mistakes

• Keep the hyphens in the standard 8-4-4-4-12 layout, since missing or extra hyphens can make an otherwise similar string invalid.
• Only hexadecimal characters are allowed, so letters outside 0-9 and a-f will fail validation.
• A UUID can be structurally valid even if it was not generated by your app, so use this tool for format checking, not for proving where the UUID came from.
• If the value includes spaces, quotes, or braces, remove them before testing unless your workflow specifically stores UUIDs that way.

Frequently asked questions