UUID generatorFree, fast and private.
Create UUIDs of every version from RFC 9562 right in your browser, one or a thousand at once. For scripts there is a free API.
This is not a valid UUID.
Enter year-month-day and a 24-hour time, in your local time. Leave empty to use the current time.
Enter a date and time like 2026-10-29 14:30.
32 hex digits, hyphens allowed. Version and variant bits are set for you. Empty means random.
Enter exactly 32 hex digits (0-9, a-f).
Generated UUID
35dfbfb4-2a81-47fd-977b-8756d1bfc54e
Created in your browser. Nothing is sent to a server.
Format
A URN always has hyphens.
Several UUIDs at once
Enter a whole number from 1 to 1,000.
What is inside a UUID?
This v7 UUID was created when the page was built. Every part has a job:
01a1bf68-d4f6-7443-8deb-6fbb7f93fe7b- Time
- Milliseconds since 1970. That is why v7 UUIDs sort by age.
- Version
- Always 7 for a v7 UUID.
- Variant
- Always 8, 9, a or b for RFC 9562 UUIDs.
- Random
- 74 random bits, so two UUIDs are practically never equal.
More tools
Decode
See version, variant and creation time of any UUID.
Validate
Check a single UUID or a whole list in one go.
Convert
Base64, Base32, integer or byte arrays for your code, and back.
Collisions
How likely is a duplicate UUID? Calculate it for v4 and v7.
ULID
Sortable IDs with 26 characters, also shown as a UUID.
NanoID
Short random IDs for URLs, in the length you need.
Snowflake IDs
Read the creation time from X and Discord IDs.
Free API
Plain REST for scripts and apps. No sign-up, no key.
Guides
Not every character in a UUID is random. Learn how the 36 characters are built and which digits reveal the version and variant.
- Format
- Version and variant
- UUID vs GUID
- Collisions
A practical guide to choosing between UUID v1, v3, v4, v5, v6, v7 and v8: what each version is good at and when to avoid it.
- v7
- v4
- v5 and v3
- v1 and v6
- v8
Random v4 UUIDs scatter inserts across the index and slow down large tables. Time-ordered v7 avoids that. With storage tips for PostgreSQL, MySQL and SQL Server.
- Index performance
- PostgreSQL
- MySQL
- SQL Server
How likely a UUID collision really is, and how UUIDs compare with ULID, NanoID, Snowflake IDs, KSUID and auto-increment numbers.
- Collision odds
- ULID
- NanoID
- Snowflake
- KSUID