UUID v6 Generator
Generate RFC 9562 version 6 UUIDs (time-sortable).
Generate sortable UUID v6 identifiers. Free, offline, runs entirely in your browser. Read more Show less
What is a UUID v6?
A UUID v6 is a modern, time-sortable UUID defined in RFC 9562 (2024). It fixes the "time ordering" issue in v1 by placing the timestamp in the most-significant bits, so v6 values sort lexicographically by creation time while keeping the same layout as v1.
For new database primary keys, v6 and v7 are both better than v4 because they cluster writes. v6 keeps the Gregorian 100-nanosecond clock of v1, while v7 uses Unix milliseconds.
FAQ
v6 vs v7
Both are time-ordered. v6 keeps v1's timestamp layout (with the order fixed); v7 uses Unix milliseconds. Pick based on your ecosystem. Most new systems prefer v7.
Why does my v6 UUID start with hex digits that look like a date?
Because the first 48 bits are the timestamp. That is the feature: UUIDs sort by creation time.
Are these values unique?
Yes, with very high probability. The clock sequence and node are random, so collisions require both the same timestamp and the same random node/sequence.