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UUID Decoder

Identify a UUID's version and variant, and extract its timestamp.

Quick Tool Overview

The UUID Decoder reads a UUID’s version and variant bits, explains what each means, and extracts the creation timestamp from the versions that carry one — including version 1’s unusual 1582 epoch.

What it does
Identifies a UUID’s version and extracts its timestamp
You give it
A UUID in any common form
You get back
Version, variant, timestamp and canonical form
Best for
Working out what an unfamiliar identifier actually is
Developer Tools Free, unlimited use No sign-up Runs in your browser

About the UUID Decoder

Every UUID carries its own version and variant in fixed bit positions, so a single identifier can tell you how it was made. This reads them and explains what each answer means, rather than just printing a number.

For the time-based versions it goes further and extracts the timestamp: version 1 and 6 count 100-nanosecond intervals since 1582, which is a genuinely strange epoch, and version 7 counts milliseconds since 1970. Either way you get a readable date. It also recognises the nil and max UUIDs, normalises whatever form you paste — braces, a urn: prefix, no hyphens, mixed case — and gives you back the canonical form.

Key features of the UUID Decoder

Every version explained

Not just a number but what it implies — whether the id is random, hashed or time-based, and what that means for sorting and privacy.

Timestamps extracted

Versions 1 and 6 count 100-nanosecond intervals since 1582 and version 7 counts milliseconds since 1970; both become a readable date.

Any input form

Braces, a urn:uuid: prefix, missing hyphens and mixed case are all accepted and normalised.

Nil and max recognised

The all-zero and all-F UUIDs are identified as the defined special values rather than as malformed input.

Variant checked too

The variant bits distinguish an RFC 4122 UUID from the legacy NCS and Microsoft layouts, which changes how the rest is read.

How to use the UUID Decoder

  1. 1

    Paste a UUID

    With or without hyphens, braces or a urn:uuid: prefix.

  2. 2

    Read the version

    Which of the eight versions it is, and what that means in practice.

  3. 3

    Check the timestamp

    Versions 1, 6 and 7 carry a creation time, which is extracted and shown as a date.

  4. 4

    Take the canonical form

    Copy the normalised UUID, or the urn: form if you need it.

Frequently asked questions

The first character of the third group. In 550e8400-e29b-41d4-a716-446655440000 that is the "4", so it is a version 4 UUID. The tool reads it and explains what the version implies.

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