Programming tool
UUID Generator
Generate secure standard UUID v4 identifiers entirely in your browser.
UUID v4 output
How it works
UUID v4 values contain 122 random bits plus fixed version and variant bits. This tool uses crypto.randomUUID when available and a crypto.getRandomValues fallback—never Math.random. UUIDs are identifiers, not passwords or secret tokens.
Worked example
Generate one UUID for a database record or a batch for test fixtures, then copy the results together.
How to use this tool
- Enter the known values and choose units where available.
- Check the primary result and supporting details.
- Clear or replace an input to calculate another case.
Frequently asked questions
What happens with invalid or incomplete inputs?
The result remains blank until the required inputs form a finite, meaningful calculation. Zero denominators and physically impossible negative quantities are not calculated.
Can I use decimal values?
Yes. The tool accepts decimals and keeps full precision for the calculation while rounding the displayed result for readability.
Can UUIDs collide?
A collision is theoretically possible but extraordinarily unlikely with a correctly generated UUID v4. Applications should still enforce uniqueness where correctness requires it.
Does generation contact a server?
No. Every UUID is generated locally by the browser's cryptographically secure random-number facilities.