UUID version 7 is the modern, time-ordered UUID standardised in RFC 9562 (2024). It embeds a Unix millisecond timestamp in its most significant bits, so v7 UUIDs sort chronologically while still containing plenty of randomness for uniqueness.
This generator produces v7 UUIDs in your browser. They combine the time-sortability of v1 with the privacy and collision resistance of v4, without exposing a MAC address.
Why UUID v7 is great for databases
Random v4 UUIDs scatter writes across a B-tree index, which hurts insert performance and cache locality on large tables. Because v7 values increase over time, new rows are appended near each other, dramatically improving index locality and write throughput.
You get sortable, roughly time-ordered primary keys without running a central sequence service and without the privacy problems of the older time-based v1.
UUID v7 structure
The layout is: 48 bits of Unix millisecond timestamp, 4 bits for the version (0111), 2 bits for the variant, and the remaining 74 bits filled with random data for uniqueness.
The result is still a standard 128-bit UUID, so it fits existing UUID and BINARY(16) columns and works with any UUID parser.
Frequently asked questions
- Is UUID v7 an official standard?
- Yes. UUID v7 is defined in RFC 9562, published in 2024, which updates the original RFC 4122.
- Should I use UUID v7 or ULID?
- Both are time-sortable 128-bit identifiers. UUID v7 stays in standard UUID format and column types; ULID uses a compact 26-character base32 string. Choose v7 for UUID compatibility, ULID for shorter URL-friendly IDs.
- Can I store UUID v7 in a UUID column?
- Yes. A v7 UUID is a normal 128-bit UUID, so it stores in UUID or BINARY(16) columns just like v4.