UUID Generator
A UUID (universally unique identifier) is a 128-bit value used as an identifier that is practically guaranteed not to collide with any other, even when generated independently across many systems. This tool generates version-4 UUIDs, which are built almost entirely from random data, making them ideal as database primary keys, request or correlation IDs, idempotency keys, and file names where you need uniqueness without a central authority handing out IDs.
Because v4 UUIDs are random, you can create them anywhere without coordination and trust that duplicates are astronomically unlikely. Generation uses the browser's cryptographically secure random source and happens entirely on your device — nothing is requested from or sent to a server. Generate one when you need a quick identifier, or several at once to seed test data or a batch of records, then copy them straight into your code, database, or config.
Generate version-4 (random) UUIDs. Examples are generated on load. Runs entirely in your browser.
Frequently asked questions
- What is a version-4 UUID?
- A 128-bit identifier generated from random data, with a few fixed version bits. Its randomness is what makes collisions effectively impossible without any central coordination.
- Are these UUIDs unique enough for database keys?
- Yes. The probability of a v4 collision is astronomically small, so they are widely used as primary keys, correlation IDs, and idempotency keys.
- Are the UUIDs generated locally?
- Yes. They are created in your browser using a cryptographically secure random source, and nothing is sent to or fetched from a server.
- Can I generate several at once?
- Yes. Generate a batch to seed test data or populate records, then copy them all out at once.
- Should I use UUIDs or auto-incrementing IDs?
- UUIDs avoid coordination and do not leak record counts, but are larger and unordered. Use them when distributed generation or non-sequential IDs matter.