UUID Generator
Generate version 4 (random) UUIDs one at a time or in bulk, with optional uppercase and hyphen-free formats. Runs in your browser.
Version 4 (random) UUIDs via crypto.randomUUID.
What is a UUID generator?
UUIDs are unique identifiers you can generate anywhere without a central database handing out IDs — perfect for primary keys, request IDs, idempotency keys and file names. This tool creates version 4 UUIDs using the browser's cryptographically secure crypto.randomUUID, so every value is drawn from strong randomness. Generate a single ID or a batch, and copy them with one click.
Where UUIDs are used
- Distributed database primary keys with no coordination.
- Idempotency and request-correlation IDs in APIs.
- Unique file, object and session identifiers.
- Message IDs in queues and event streams.
How to use it
- 1Set how many UUIDs you need.
- 2Optionally switch to uppercase or drop the hyphens.
- 3Copy any single UUID, or use Copy all for the batch.
- 4Hit Regenerate for a fresh set.
Frequently asked questions
What is a UUID?+
A UUID (Universally Unique Identifier) is a 128-bit value written as 32 hexadecimal digits in five hyphen-separated groups, like 3f2504e0-4f89-41d3-9a0c-0305e82c3301. It's designed to be unique without a central authority.
What is a version 4 UUID?+
A v4 UUID is generated from random data (with a few bits fixed to mark the version and variant). It's the most common type because it needs no coordination — just a good random source, which this tool uses via crypto.randomUUID.
Are UUIDs guaranteed to be unique?+
Not mathematically guaranteed, but the collision probability for random v4 UUIDs is astronomically small — you'd need to generate billions before a collision becomes likely. For practical purposes they're unique.
Can I generate many at once?+
Yes, up to 100 at a time. Use 'Copy all' to grab the whole batch, or copy any single UUID from its row.