UUID v7 Generator
Generate RFC 9562 version 7 UUIDs (time-ordered, sortable).
Generate time-ordered UUID v7 identifiers. Free, offline, runs in your browser. Read more Show less
What is a UUID v7?
A UUID v7 is a modern time-ordered UUID, standardized in RFC 9562 (2024). The first 48 bits are a Unix millisecond timestamp, followed by 74 bits of randomness. This means UUID v7 values sort lexicographically by creation time while remaining globally unique.
For database primary keys, v7 is generally preferable to v4 because the sortable prefix improves index locality and reduces write amplification in B-tree storage.
FAQ
When should I use v7 instead of v4?
Whenever the IDs will be stored or indexed. v4 remains fine for ephemeral identifiers that are never sorted.
Are these fully random?
The last 74 bits are random, generated with the browser cryptographic random source. The first 48 bits are the current time in milliseconds, so two IDs generated in the same millisecond differ only in the random portion.
Is UUID v7 supported everywhere?
RFC 9562 was published in May 2024. Support varies; the format is stable and easy to generate without a library.