UUID Parser
Break a UUID into version, variant and embedded timestamps — v1 carries MAC and time, v7 stores a millisecond timestamp in its first 48 bits; decode it locally with ease.
>_ USAGE GUIDE
Paste a UUID and the tool breaks it into version, variant and any embedded timestamp. The version nibble tells you how it was generated, the variant records the layout convention, and the time-bearing versions v1 and v7 can be decoded back to a human-readable local time for tracing where an ID came from.
The versions differ in useful ways. v1 embeds a timestamp plus the generating machine's MAC address, so it is time-based and can leak machine identity. v7 stores a millisecond timestamp in its first 48 bits, big-endian, giving millisecond precision when decoded. v4 is fully random with no time or machine data, while v3 / v5 are name-based and carry no timestamp. The version and variant nibbles sit at fixed positions and the tool labels what each one means.
- Paste the UUID: enter a standard hyphenated UUID string
- Read version and variant: see the version number and the variant explanation
- Decode the timestamp: v1 / v7 show both ISO (UTC) and local time
- Copy the result: take the parsed fields with you
>_ FAQ
Q1 · How do I spot the version number at a glance?
Look at the first character of the third group — the 15th character overall, in the xxxxxxxx-xxxx-Mxxx-... shape. That nibble is the version: 1 for v1, 4 for v4, 7 for v7, and so on. The tool reads and labels it for you.
Q2 · Why can v1 reveal a creation time and MAC address?
v1 uses a time-plus-node layout: the front holds a 60-bit timestamp counting 100-nanosecond ticks since 1582-10-15, and the back by default holds the generating machine's MAC address (the node). So a v1 lets you recover the time and even infer which machine produced it — exactly why it is considered a privacy risk.
Q3 · How is the v7 timestamp encoded?
v7 puts a Unix millisecond timestamp in its leading 48 bits, big-endian, with the remaining bits used for randomness to keep IDs unique. Decoding reads those 48 bits as an integer to get millisecond time: coarser than v1's 100-nanosecond ticks but more compact and friendlier to database ordering.
Q4 · What if the decoded value does not match my expectation?
First confirm the value is a standard UUID with the right length and hyphens. If the time looks off, a mixed-up timezone is the usual cause — the tool shows both ISO (UTC) and local time to compare. If the version surprises you, the original value probably is not that version; the tool parses faithfully and never rewrites the content.
Q5 · How does it differ from the UUID generator?
The generator produces batches of v4 UUIDs, optionally uppercase or without hyphens. This tool decodes: it breaks an existing UUID into version, variant and embedded time. They run in opposite directions, one to create and one to read.