How to use UUID v4 generator
Generate random version-4 UUIDs with the browser’s cryptographic random source. The check runs when you submit the form. Its inputs are processed in this browser.
How the check works
crypto.randomUUID() produces version-4 identifiers using cryptographically secure randomness. You can request one to one hundred at a time.
The Overview tab explains the findings. Measured data lets you search individual fields and values, while JSON report shows the complete export. Export JSON to retain a baseline, or print the findings for your own records. Review the report before sharing it: browser characteristics, token claims, and file names can reveal information about your setup.
Read the result in context
UUID v4 includes 122 random bits after its fixed version and variant bits. Random identifiers make accidental collisions extremely unlikely at ordinary scales.
Understand the limits
A UUID is an identifier, not an authentication or authorisation decision. Generated values are included in the downloadable report.
Common questions
Where is the input processed?
In this browser tab. This tool does not submit its input to the site server or a third-party service.
What should I keep with a result?
Record the selected options, browser and time. Review exported values before sharing them. Generated passwords, tokens and HMAC secret keys are excluded from report exports.