UUID Generator
Generate random version-4 UUIDs (GUIDs) with a click, using your browser's crypto.
A UUID is a 128-bit identifier unique enough to use as a key without a central authority handing them out. UUID Generator creates random version-4 UUIDs on demand using your browser's secure randomness — handy for database keys, test data and request IDs.
How to use uuid generator
- 1. Open the tool.
- 2. Generate one or more version-4 UUIDs.
- 3. Copy the UUID(s).
When to use UUID Generator
Database keys
Generate unique identifiers for records without coordinating IDs.
Test data
Produce realistic unique IDs while developing or testing.
Request and trace IDs
Create a unique ID to tag a request or event.
Anatomy of a version-4 UUID
A UUID is 36 characters: 32 hex digits in groups of 8-4-4-4-12. In version 4, the first digit of the third group is always 4 and the first digit of the fourth group is 8, 9, a or b; the other 122 bits are random. They're created with your browser's crypto.randomUUID(). Even generating a billion UUIDs per second, it would take about 86 years before the chance of a single duplicate reached one in two. Use "Generate 10" for a batch.
Frequently asked questions
What version of UUID is generated?
Random version 4, generated from your browser's cryptographic randomness.
Are they guaranteed unique?
Collisions are astronomically unlikely for v4 UUIDs, which is why they're used as keys without central coordination.
Is anything uploaded?
No — UUIDs are generated locally in your browser.
Is a GUID the same thing?
Yes — GUID is Microsoft's name for the same 128-bit format. Ours are in lowercase; UUIDs are case-insensitive, so convert to uppercase if a system insists.