UUID generator
Generate v4 UUIDs
Choose a count from 1 to 1000 — each one is generated independently and randomly.
This tool runs entirely in your browser. UUIDs are generated locally and never sent to a server.
About this tool
A UUID (Universally Unique Identifier) is a 128-bit identifier standardized by RFC 4122. Version 4 UUIDs are generated from random (or pseudo-random) data, making collisions statistically negligible — there are approximately 5.3 × 10²⁶ possible v4 UUIDs. They are used wherever a unique identifier is needed without central coordination, such as database primary keys, session tokens, file names, and distributed system event IDs. This tool generates up to 1,000 UUIDs at a time using the Web Crypto API.
Common uses
- › Generating primary keys for database records
- › Creating unique identifiers for distributed system events
- › Seeding test data with realistic-looking IDs
- › Generating unique file or resource names
- › Producing correlation IDs for request tracing
Example
Count: 3f47ac10b-58cc-4372-a567-0e02b2c3d479
9b1deb4d-3b7d-4bad-9bdd-2b0d7b3dcb6d
3c9f8a2e-1d4b-4e5a-8f6c-7a1b2c3d4e5fTechnical notes
- › Version 4 UUIDs are random, not sequential — they carry no information about creation order or time, unlike UUID v1 or v7.
- › The chance of two v4 UUIDs colliding is astronomically small, but not mathematically zero; for most applications this risk is negligible.
- › This tool uses the browser's built-in crypto.randomUUID(), which is cryptographically secure and does not require any external library.
FAQ
Are UUIDs generated here truly random?
Yes. This tool uses the Web Crypto API's randomUUID() function, which draws from a cryptographically secure random number source rather than a predictable pseudo-random generator.
Can two UUIDs ever be the same?
In theory, yes, but the probability is so low (roughly 1 in 2.7 × 10¹⁸ for a collision among a billion UUIDs) that it's not a practical concern for almost any application.
What's the difference between UUID v4 and other versions?
UUID v1 encodes a timestamp and network identifier, v4 is fully random, and newer v7 is time-ordered for better database indexing. This tool generates v4, the most common general-purpose choice.