MongoDB ObjectID decoder
A MongoDB ObjectID is 12 bytes (24 hex characters): a 4-byte unix-seconds timestamp, a 5-byte random value generated per-process, and a 3-byte incrementing counter.
objectid (24 hex)
decoded
- created at
- -
- unix seconds
- -
- relative
- -
- timestamp hex
- -
- random hex
- -
- counter
- -
layout
ObjectID structure:
4 bytes · big-endian unix seconds (good until 2106).
5 bytes · per-process random value (stable within a driver instance).
3 bytes · incrementing counter (random initial value per process).
A 5-byte random value isn't a machine ID anymore - the modern spec replaced the old machine+PID layout.
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