UUID generator

Create between 1 and 100 version 4 UUIDs for test objects, API resources or imported records. Each request produces a new batch in your browser without contacting a remote generation service. Identifiers appear one per line and can be displayed in uppercase. Choose this version when you need independent random identifiers: a v4 UUID contains no creation date and does not put records into chronological order.

A UUID contains 128 bits and is normally written as 32 hexadecimal digits with four hyphens in groups of 8-4-4-4-12. Version 4 reserves bits for its version and variant; the remaining 122 bits are random. The third group starts with 4, and the fourth with 8, 9, a or b. These markers describe the format but do not, by themselves, prove that a generator uses good randomness.

The tool requests each value from crypto.randomUUID, the browser’s cryptographic API. It needs a compatible browser and a secure context, usually HTTPS or localhost. Quantity must be a whole number between 1 and 100: empty, fractional and out-of-range inputs are rejected. An unavailable API produces a different message from an invalid quantity.

Changing case only changes how hexadecimal letters are written; uppercase and lowercase represent the same identifier. Clicking Generate again, however, produces new values. Editing the options hides the previous list so it cannot be mistaken for a batch generated with the new settings. Save any list you need before starting another generation.