UUIDv7 Generator
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Validate
Timestamp (estimated)
UUIDv7 embeds a Unix timestamp (milliseconds) at the beginning.
How to use
Click “Generate” to create a UUIDv7. Pasted values are also validated automatically and the timestamp is shown.
What this tool validates
- Format: hex-and-dash (8-4-4-4-12)
- Version: version field is 7
- Variant: variant is 0b10 (RFC4122)
Notes (this tool)
- “Valid” means format/spec compliant. It does not guarantee uniqueness (no collisions) or security.
- The timestamp is estimated from the embedded millisecond value (order within the same ms is not known).
- Older systems/libraries may reject v7 because they don’t support it yet. Check your runtime ecosystem.
About UUIDv7
What is UUIDv7?
UUIDv7 is a time-ordered UUID that stores a Unix Epoch timestamp in milliseconds in the most significant 48 bits.
Because it carries time information while keeping the UUID format, it can be handy for DB primary keys, log/event IDs, and correlation IDs.
Key points (from the RFC)
- The string form is hex-and-dash (upper/lower/mixed case allowed).
- unix_ts_ms is a 48-bit big-endian unsigned Unix timestamp in milliseconds.
- The Version field is bits 48–51; v7 means value 7.
- For RFC UUIDs, the Variant is 0b10 (RFC4122).
- Remaining bits provide uniqueness; implementations may also use constructs for monotonicity.
FAQ (UUIDv7)
How is it different from UUIDv4?
UUIDv4 is primarily random; UUIDv7 embeds time (milliseconds) in the most significant bits.
Is the timestamp exact?
We extract the embedded millisecond value. Order within the same millisecond can’t be reconstructed, so treat it as an estimate.
Is uniqueness guaranteed?
UUIDs are designed to make collisions extremely unlikely, but not mathematically impossible. Design accordingly for your use case.
References (RFC)
- RFC 9562 §5.7 (UUIDv7 structure)
- RFC 9562 §4 (string format / ABNF)
- RFC 9562 §4.1 / §4.2 （Variant / Version）
Example
0193f0c0-2a2b-7b9d-b5a9-2a6e0c7b3a8e