Generate v4 or time-ordered v7 UUIDs in bulk, and decode the version, variant and timestamp of any UUID.

v4 or v7?

	v4	v7
Contents	122 random bits	48-bit Unix ms timestamp + 74 random bits
Sorts by creation time	no	yes
As a database key	scatters inserts across the index	appends, like an auto-increment
Leaks creation time	no	yes, to the millisecond

Within one millisecond, this generator uses the 12-bit rand_a field as a counter (RFC 9562 method 1), so a batch of v7 IDs is strictly increasing.

Inspecting

Paste any UUID (with or without hyphens, braces or urn:uuid:) to see its version and variant. Time-based versions (v1, v7) also show the embedded timestamp.

References

RFC 9562 — Universally Unique IDentifiers

UUID Generator & Inspector

v4 or v7?

Inspecting

References

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