Distributed systems often need identifiers that can be generated independently without coordinating a central counter. UUID Generator creates identifiers in the standardized UUID format, with the exact generation rule depending on the version supported by the tool.
Different UUID versions solve different problems: version 4 is primarily random, while newer time-ordered formats such as version 7 incorporate timestamp information. UUIDs are designed to make accidental collisions extremely unlikely in normal use, but they are identifiers—not passwords, access tokens, or proof of authenticity.
How to use this tool
How does the UUID Generator work?
How to use UUID Generator
- Generate a UUID using the options provided by the tool.
- Choose a version only when the application you are integrating with requires a specific UUID version.
- Copy the complete generated identifier.
- Validate the expected format before storing or transmitting it.
- Do not treat a UUID as a password, access token, or secret merely because it is difficult to guess.
Technical reference
Current UUID versions and structure are defined in RFC 9562 – Universally Unique IDentifiers.
Examples
UUID v4 sample
A v4 UUID has the familiar 8-4-4-4-12 hexadecimal layout with version/variant bits set according to the UUID standard.
Bulk IDs
Generate separate UUIDs for test fixtures or records instead of incrementing a manually maintained string.
Database key
A UUID can be generated independently of a central integer sequence, which is useful in distributed systems.
Not a secret
A UUID is an identifier, not an authorization mechanism; access control must not depend on its obscurity.
Common use cases
- Database primary keys
- API resource IDs
- Test data
- Distributed systems
- Client-side temporary IDs
- Event identifiers
Frequently asked questions
What is a UUID?
A UUID is a 128-bit identifier represented in a standardized textual format. Different UUID versions generate the identifier using different rules.
What is UUID version 4?
Version 4 UUIDs are generated primarily from random bits, with specific bits reserved to identify the version and variant.
What is UUID version 7?
Version 7 UUIDs place a Unix-epoch timestamp near the beginning and combine it with randomness, which makes generated values broadly time-sortable.
Are UUIDs guaranteed never to collide?
No finite identifier space can offer an absolute mathematical guarantee, but correctly generated UUIDs are designed to make accidental collisions extremely unlikely for ordinary use.
Can a UUID be used as a password or security token?
Not automatically. An identifier and a secret serve different purposes. Use a security mechanism designed for authentication or authorization when secrecy matters.