Boring Tools

UUID Generator

Open tool

Generate random UUID v4 identifiers in bulk.

Generate random version 4 UUIDs (also called GUIDs) — 36-character identifiers such as 3b241101-e2bb-4255-8caf-4136c566a962 — one at a time or up to 100 in a batch. Handy for database keys, test data, and anywhere you need an ID that will not collide.

How it works

Each identifier comes from your browser's crypto.randomUUID(), which draws from the operating system's cryptographically secure random source. A version 4 UUID is 122 random bits plus a few fixed bits that mark its version, so the chance of two ever matching is negligible.

Five UUIDs are generated automatically when the page opens.

How to use it

  1. Set How many? to the number of UUIDs you want (1–100).
  2. Click Generate. Each click replaces the list with a fresh batch.
  3. Click Copy to put the whole list on your clipboard, one UUID per line, or Download to save it.

Options & controls

Controls

How many? (max 100)
A whole number from 1 to 100. Values outside that range are clamped when you click Generate — 0 or less gives 1, more than 100 gives 100. Default: 5.
Generate
Creates a new batch and replaces the old one.
Copy
Copies every UUID in the list, separated by line breaks.
Download
Saves the list as uuids.txt, one per line.
Reset
In the title row. Empties the list. It does not change the How many? number — click Generate to fill it again.

The list

UUID box
Read-only. Shows up to 15 lines at a time and scrolls if you generated more.

Tips & guidelines

  • The UUIDs are lowercase with hyphens. If you need uppercase or no hyphens, use your editor's find-and-replace after copying.
  • Generating in bulk is fine for test fixtures, but each UUID is independent — the tool does not remember previous batches, so regenerating never guarantees uniqueness across separate sessions (though collisions are, for practical purposes, impossible).

Limits

  • Only version 4 (random) UUIDs are supported — no v1, v5, v7, or nil/max UUIDs, and no custom formats.
  • Generation needs a secure browsing context (an https page, or localhost). Very old browsers that lack crypto.randomUUID cannot generate UUIDs at all.

Saved in your browser

Nothing. The generated list exists only on the page and is gone when you refresh.

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