UUID validator and decoder
Paste any id with or without hyphens, in braces or as urn:uuid, and the tool checks its structure against RFC 9562 and explains what it holds.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Enter uuid.
- The result appears straight away and updates as you edit.
- Copy the result, or copy a link that keeps the same values to share it.
How it is calculated
The format is 32 hex characters grouped 8-4-4-4-12. The version is the 13th character and the variant comes from the top bits of the 17th. Version 7: time = first 48 bits in ms. Versions 1 and 6: time in 100 ns units since 15 October 1582.
Example
Inputs: UUID = 017f22e2-79b0-7cc3-98c4-dc0c0c07398f. Result: Result: Valid UUID; Version: Version 7 (Unix time); Variant: RFC 9562 (OSF DCE).
017f22e2-79b0-7cc3-98c4-dc0c0c07398f
017f22e2-79b0-7cc3-98c4-dc0c0c07398f
Limits and caveats
- It checks structure only and cannot know whether the id exists in your system or was used before.
- Times in versions 1 and 6 are shown to the millisecond even though the id stores 100 ns precision.
Questions about this tool
Is an uppercase UUID valid?
Yes, letter case does not change the value, though RFC 9562 recommends lowercase for the canonical form, which the tool shows.
How can I spot the version at a glance?
Look at the first character of the third group; in 550e8400-e29b-41d4 the 4 means version 4.
Does a UUID v1 reveal a MAC address?
Its last 12 characters may hold the MAC address of the machine that created it, which is why many systems moved to v4 or v7.