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UUID Validator & Decoder

Paste one or more UUIDs to check they're valid and see what's inside: the version and variant, and for time-based UUIDs (versions 1, 6 and 7) when they were created, plus the clock sequence and node of versions 1 and 6. Each comes with its other notations and a regex for its version. Nothing is uploaded.

Runs in your browser

UUIDs

One per line

Results

Paste a UUID to validate and decode it.

Reading a UUID

In xxxxxxxx-xxxx-Mxxx-Nxxx-xxxxxxxxxxxx, the digit at M is the version and the first one or two bits of N the variant. For standard UUIDs, N is 8, 9, a or b. Version 4 is random; versions 3 and 5 are hashes of a name; versions 1, 6 and 7 contain a timestamp.

  • v7 starts with a Unix timestamp in milliseconds, so it sorts by creation time: the recommended choice for new database keys.
  • v1 stores a 60-bit count of 100-nanosecond intervals since 15 October 1582, split and reordered, plus a clock sequence and a node, originally the MAC address.
  • v6 is v1 with the timestamp reordered so it sorts by time.

How to use the UUID Validator & Decoder

  1. Paste one or more UUIDs, one per line, or press Sample. Braces, urn:uuid: and missing hyphens are accepted.
  2. Read the version, variant and, for time-based UUIDs, the creation time.
  3. Copy another notation, or the regex that matches UUIDs of this version.

Examples

A version 7 UUID

Input
017F22E2-79B0-7CC3-98C4-DC0C0C07398F
Output
Version 7, created 2022-02-22T19:22:22.000Z

The example from RFC 9562. The first 12 hex digits, 017f22e279b0, are the milliseconds since 1970.

The same moment in a version 1 UUID

Input
C232AB00-9414-11EC-B3C8-9F6BDECED846
Output
Version 1, created 2022-02-22T19:22:22.000Z

The timestamp's parts are stored in reverse order (11ec 9414 c232ab00), which is why v1 UUIDs don't sort by time.

A random version 4 UUID

Input
{919108F7-52D1-4320-9BAC-F847DB4148A8}
Output
Version 4

Braces and uppercase, as Microsoft tools write GUIDs, are accepted.

Privacy

A time-based UUID reveals when it was created, and a v1 UUID may reveal the MAC address of the machine that made it. Avoid them for identifiers that must not leak this, such as public links; use v4.

Limitations

  • Version 2 (DCE security) UUIDs are recognised but their local domain and ID aren't decoded.
  • The names behind version 3 and 5 UUIDs can't be recovered: they're hashes.

Frequently asked questions

Are my UUIDs uploaded?

No. Validation and decoding happen in your browser; nothing you paste is sent anywhere.

What regex validates a UUID?

^[0-9a-f]{8}-[0-9a-f]{4}-[1-8][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$ with the i flag accepts any standard UUID; replace [1-8] with a single digit to accept one version. Each result shows the regex for its version.

Can I get the creation date of a v4 UUID?

No. Version 4 UUIDs are random and contain no time. Only versions 1, 6 and 7 do.

How do I generate UUIDs?

Use the UUID Generator for v4 and v7 UUIDs.