UUID Generator
Generate random UUID v4 identifiers in bulk — cryptographically random, locally.
Free · No sign-up · Runs locally in your browser · Also available in Chinese (中文)
What is UUID Generator?
A UUID generator produces 128-bit identifiers that are unique in practice without any central registry. Version 4 UUIDs derive their uniqueness from randomness: 122 random bits means the chance of two generated UUIDs ever colliding is negligible even at planetary scale.
Use UUIDs wherever entities need stable IDs that cannot reveal sequence information — database primary keys, distributed systems, file names, request trace IDs. The generator uses your browser's cryptographic RNG and can produce many UUIDs at once, formatted in lowercase, uppercase or without hyphens.
How to use it
- 1Choose how many UUIDs you need — one or a bulk list.
- 2Select formatting options such as uppercase or no hyphens if your system requires them.
- 3Click generate; identifiers appear instantly.
- 4Copy the list or download it as a text file.
Common use cases
- Seeding a database with test records that have realistic, unique IDs.
- Naming uploaded files so filenames never collide or leak sequence info.
- Creating correlation IDs for tracing requests across services.
Frequently asked questions
▸Can a generated UUID collide with an existing one?
The probability is astronomically small — you would need to generate billions per second for centuries to expect one collision with v4's 122 random bits.
▸Are UUIDs safe to expose publicly?
They are not secrets, but they are also not guesses: unlike sequential IDs, a UUID v4 cannot be enumerated, which is a useful property for resource URLs.