UUID Generator
Generate random UUID v4 identifiers, one or many at a time.
UUIDs (v4) are generated locally in your browser using the Web Crypto API.
About this tool
This tool generates version 4 (random) UUIDs using your browser's Web Crypto API. UUIDs are commonly used as unique identifiers for database records, API requests, sessions and objects in distributed systems.
Because v4 UUIDs are derived from 122 bits of randomness rather than a central counter, any two systems — or any two calls to this tool — can generate IDs independently with a vanishingly small chance of ever producing the same value twice.
Generate a single UUID for a one-off need, or bulk-generate up to 50 at once (for seeding test data, for example) and copy them all with one click.
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Frequently asked questions
- What is a UUID?
- A UUID (Universally Unique Identifier) is a 128-bit identifier, usually written as 32 hexadecimal characters split into five groups (e.g. 550e8400-e29b-41d4-a716-446655440000), that is practically guaranteed to be unique without any central coordination.
- Is it safe to generate UUIDs online?
- Yes — this tool generates UUIDs locally in your browser using the Web Crypto API's cryptographically secure random number generator. No data is sent to any server, and there's nothing sensitive in a UUID itself since it doesn't encode any information about you.
- What does 'v4' mean, and how likely is a collision?
- Version 4 UUIDs are generated from random bits rather than derived from a timestamp or hardware address. With 122 random bits, the probability of two independently generated v4 UUIDs colliding is astronomically small — you could generate billions per second for centuries and still be extremely unlikely to see a duplicate.
- What are UUIDs commonly used for?
- UUIDs are widely used as database primary keys, API request IDs, session tokens, and object identifiers in distributed systems — anywhere you need a unique ID that different systems can generate independently without checking with each other first.