UUID Generator
Generate random UUID v4 identifiers, one at a time or in bulk.
How to use UUID Generator
- Choose how many UUIDs to generate (1 to 100).
- Optionally switch to uppercase or remove hyphens.
- Click Generate — copy a single UUID or all of them at once.
About this tool
The UUID Generator creates version 4 (random) UUIDs — 128-bit identifiers that are, for practical purposes, guaranteed unique without needing a central authority to assign them. Generate a single UUID or up to 100 at once, with optional uppercase formatting or hyphens removed. Generation uses your browser's built-in cryptographically secure random number generator — nothing is uploaded or sent to a server.
Frequently Asked Questions
What is a UUID v4?
A UUID (Universally Unique Identifier) version 4 is a 128-bit identifier made mostly of random bits, formatted as 32 hex digits in the pattern 8-4-4-4-12 (e.g. f47ac10b-58cc-4372-a567-0e02b2c3d479). The odds of two randomly generated v4 UUIDs colliding are astronomically small.
Are these UUIDs cryptographically secure?
Yes — generation uses the browser's built-in crypto.randomUUID() API (or an equivalent cryptographically secure random source as a fallback), the same underlying randomness used for security-sensitive operations, not a weaker Math.random()-based generator.
Can I use these as database primary keys?
Yes, UUIDs are commonly used as primary keys, especially in distributed systems where IDs need to be generated independently without coordination. Keep in mind UUIDs are larger than auto-incrementing integers, which has minor storage and indexing trade-offs.