UUID v4 Generator
Create one to 100 random UUID v4 identifiers for development records and synthetic fixtures.
Local processing · No account · Input is not uploaded by this tool
How to use this tool
- Choose the relevant options. Set the operation, format or algorithm before running. The options above define how the result is interpreted.
- Enter data or load an example. Generate three IDs; each has a 4 in the version position and an RFC variant nibble.
- Run and inspect the feedback. Use the primary action, then read the status message. An error clears old output so it cannot be mistaken for a fresh result.
- Copy, download or start again. Copy and Download become available when a current nonempty result exists. Reset clears the text result; no input is stored by this site.
How it works
crypto.getRandomValues creates 16 bytes; version and variant bits are set before formatting the conventional 8-4-4-4-12 hexadecimal groups.
The computation is performed by this page’s JavaScript after you choose Run. Input and results are kept in the current tab’s memory. There is no background submission, analytics event containing your input, or server-side conversion in this build.
Practical example
Use Load example to try the supported format, then change one value and run again. Comparing those two results is a quick way to understand what the operation changes and what it preserves. The linked guides below provide worked examples for the edge cases relevant to this utility.
Common mistakes
Do not use a short UUID prefix as the only unique storage key. Use fixed synthetic IDs when reproducible snapshots matter.
Limits and unsupported tasks
Not time-sortable and not a guarantee of zero collisions. Retain database uniqueness constraints. An identifier does not grant permission. Secure random API support is required.
Privacy and handling sensitive data
The generator has no user-supplied record content to upload. Random bytes are obtained locally from the browser API. Generated IDs are held in the output field, and neither their values nor a batch history are sent to this website. Copy and Download use your device. Browser extensions and hosting logs have separate boundaries, explained in the privacy policy.
Usage guides
Questions, answered
Does the UUID v4 Generator upload my input?
No. The implementation processes it in your browser and does not submit it to a server. Ordinary page requests still reach the hosting service.
Why did Copy or Download become unavailable?
The input changed or validation failed, so the previous output was cleared. Run the tool again to create a current result.
Can I use this for every production workflow?
Not time-sortable and not a guarantee of zero collisions. Retain database uniqueness constraints. An identifier does not grant permission. Secure random API support is required.