UUID Generator
Generate version 4 UUIDs (universally unique identifiers) instantly. Bulk generate up to 100 at once.
What is a UUID and when should you use one?
A UUID (Universally Unique Identifier) is a 128-bit ID designed to be unique across all space and time — without a central registry assigning them. Version 4 UUIDs are randomly generated and look like: 550e8400-e29b-41d4-a716-446655440000
Common use cases:
- Database primary keys — avoids sequential IDs that reveal record counts and create merge conflicts in distributed systems.
- Session & API tokens — random, non-guessable IDs for temporary sessions or request tracking.
- File & object names — unique names for uploaded files to prevent collisions without checking the filesystem.
- Idempotency keys — ensure a payment or API request isn't processed twice even if retried.
- Correlation IDs — trace a single request across multiple microservices in logs.
How to Use
- Set how many UUIDs you need (1–100).
- Choose lowercase or uppercase format.
- Click Generate and copy or download.
FAQ
What is UUID v4?
UUID v4 is a randomly generated 128-bit identifier in the format xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx. The "4" indicates version 4 (random). It's the most common UUID version for application IDs.
Are UUIDs truly unique?
The probability of two v4 UUIDs colliding is astronomically small — roughly 1 in 5.3 × 10³⁶. For practical purposes, they are unique.
Is my data stored?
No. UUIDs are generated entirely in your browser using crypto.randomUUID().