What this tool does
UUID Generator
Your input is sent to the server for this request and is not saved as a tool content record. Infrastructure logs may still record request metadata, so do not submit secrets.
Choose UUID version 4 for random identifiers or version 1 when its time-and-node-based format is explicitly required. Set the batch count, letter case, and hyphen formatting before copying the output.
How to use this tool
How to use UUID Generator
Choose how many UUIDs you want.
Pick the UUID version.
Generate and copy the result.
Before and after example
UUID Generator example
Output
550e8400-e29b-41d4-a716-446655440000Options, errors, and limitations
UUID Generator options and common errors
Parent category
Explore the Security Tools hub
Developer utilities for JWT inspection, hashing, regex review, and safe encoding workflows.
Related articles
Read more from the developer blog
FAQ
UUID Generator FAQ
What is the difference between UUID version 4 and version 7?
UUID version 4 is random based, while UUID version 7 combines a Unix timestamp with additional bits to produce identifiers that are roughly time ordered. Version 7 can improve index locality in databases while retaining a very large uniqueness space.
How likely is a UUID collision?
With correctly generated UUIDs, collisions are extraordinarily unlikely for normal application volumes. The practical risk is usually much lower than failures caused by poor random number generation, implementation bugs, or accidentally reusing identifiers.
Can I use a UUID as a database primary key?
Yes. UUIDs are common primary keys in distributed systems because IDs can be generated independently of a central database sequence. Consider storage format, index locality, and version choice when performance matters.
Is a UUID a secure secret or access token?
No. A UUID is an identifier, not an authorization control. Some UUID versions are hard to guess, but sensitive resources still require proper authentication and permission checks.
Are UUID version 7 values sortable by creation time?
They are designed so the timestamp portion gives them useful time ordering when represented consistently. That makes them attractive for database indexes and event identifiers, but applications should not use the UUID alone as a trusted timestamp.
Why are UUIDs 36 characters long when written as text?
The common textual form contains 32 hexadecimal digits plus four hyphens, for a total of 36 characters. The underlying UUID is 128 bits regardless of the text formatting.
Does uppercase or lowercase change a UUID?
No. Hexadecimal letters in the standard text representation are case insensitive. Systems often normalize UUIDs to lowercase for consistency.
Should my application still enforce a unique database constraint on UUIDs?
Yes. Even when collisions are astronomically unlikely, a unique constraint protects data integrity against collisions, bugs, duplicate imports, and accidental reuse.
Can UUIDs be generated offline or on multiple servers?
Yes. One major advantage is that many UUID versions can be generated independently on separate machines without requesting a central sequence value first.
Does UUID version 1 expose information about the machine?
Traditional version 1 UUIDs include a timestamp and node identifier historically derived from a MAC address, which can reveal metadata. Modern UUID specifications and implementations provide alternatives when privacy or predictability matters.