A UUID is not just a random string. Its bits encode a version and variant, and time-based versions carry a real timestamp. The decoder reads those fields back out so you can tell what a UUID is and, when applicable, when it was created.
Key takeaways
- Identifies the UUID version and RFC variant.
- Extracts the creation timestamp from UUID v1, v6 and v7.
- Runs entirely in your browser with no upload.
What the decoder reads
Every UUID reserves a few bits for structure. The first character of the third group encodes the version, and the first bits of the fourth group encode the variant. The decoder normalizes your input, reports both, and confirms whether the value follows the RFC 9562 variant.
Extracting a timestamp
Time-based UUIDs embed the moment they were generated. UUID v7 stores a Unix millisecond timestamp in its first 48 bits. UUID v1 and UUID v6 store a 60-bit count of 100-nanosecond intervals since 15 October 1582. The decoder converts either form into a normal date and time.
Random UUID v4 and name-based UUID v3 and v5 do not encode a timestamp, so the decoder reports that no embedded time is available for those versions.
018f2f7a-07b2-7d6e-9c37-43e1577b8b44
^^^^^^^^^^^^ version 7: first 48 bits = Unix ms timestampWhy decode a UUID
Decoding is handy when debugging: you can confirm that an ID really is the version you expect, spot a v4 where a v7 was intended, or read the creation time straight out of a log identifier without a separate timestamp column.