Developer Tools

UUID Generator

Generate UUID v4 identifiers privately using your browser’s cryptographic randomness. Create a single value or a batch, choose case and output format, then copy or download.

Your content stays on your device Free, with no account
Fresh identifiers, generated on your device UUID v4 · browser randomness

Choose your UUID output

Generate 1–1,000 UUID v4 values per batch.

UUID v4 uses random values rather than a timestamp or device identifier. Generation uses the browser’s cryptographic randomness; there is no weak-random fallback.

YOUR UUIDS

Ready. Generate a fresh batch when you need it.

Generate again replaces the current batch. UUIDs are random identifiers with a very low collision probability, not a guarantee of global uniqueness. No results are uploaded or saved.

A FEW SIMPLE STEPS

How to use UUID Generator

  1. Choose how many UUID v4 identifiers to generate, from 1 to 1,000.
  2. Select one per line, a comma-separated list or a JSON array, and choose lowercase or uppercase.
  3. Select Generate UUIDs. Review the batch or generate again to replace it with fresh values.
  4. Copy the output or download TXT/JSON. Editing settings or Clear result removes the old batch.
PRIVATE BY DESIGN

Why use this tool?

Generation happens entirely on your device with the browser’s cryptographic random source. No request is sent to a UUID service, and no identifiers or options are saved in browser storage. There are no dependencies, accounts, uploads or device identifiers in the generated values.

Tool inputs stay in your browser. Only your theme preference is saved on this device.

A few things worth knowing

Which UUID version and format are generated?

UUID version 4 with the standard version and variant bits, displayed in the 8-4-4-4-12 hexadecimal layout. Hyphens are always included. UUID and GUID are often used for the same identifier format. This tool does not generate time-ordered UUID v7 or namespace-based versions.

What randomness is used?

The tool requests 16 bytes per identifier from crypto.getRandomValues and sets the version/variant bits, leaving 122 random bits per UUID v4. No Math.random fallback is used. If browser cryptographic randomness is unavailable or fails, the run gives no output rather than substituting weaker values.

Are UUIDs guaranteed to be unique?

No random generator can promise that an identifier has never appeared elsewhere. UUID v4 is designed for an extremely low collision probability, not a central global uniqueness check. The tool does not contact a registry or maintain a history. Use your application’s normal uniqueness constraints where required.

What output formats can I download?

One-per-line and comma-separated lists download as UTF-8 TXT. JSON mode downloads a UTF-8 JSON array containing UUID strings. Letter case affects only hexadecimal letters, not the identifier bits. Export contains only the current generated batch without report headings or metadata.

Can I generate batches or keep a previous batch?

Generate 1–1,000 UUIDs per run. Generating again replaces the current result, and changing count, case or format clears it. Copy or download a batch before replacing it if you need to keep it. Clear result preserves your selected settings. No automatic generation occurs on page load.

Is anything saved or uploaded?

No. Generated values remain in the page until you copy or download them, change settings, clear or leave. Input settings and result history are not stored. Only the site’s theme preference is saved. Generation requires a browser with crypto.getRandomValues support.