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UUID generator

Generate one UUID or a batch of up to 100 with a click, using your browser's cryptographic random number generator (crypto.randomUUID, with a manual fallback for older or non-secure contexts). Nothing is sent to a server, so the IDs are yours the moment they appear.

  • Nothing you type leaves this page
  • Works offline once loaded
  • Free forever, no signup
  • {{ id }}

How to use this tool

  1. Pick how many you need

    Use a preset (1, 10, 25, 100) or type any number up to 100.

  2. Set formatting options

    Toggle uppercase letters and hyphens on or off to match what your system expects.

  3. Copy one or copy all

    Each row has its own copy button, or grab the whole list at once with Copy all.

Questions people ask

What is a UUID v4?

A 128-bit identifier that is almost entirely random, defined by RFC 9562. Six of those bits are fixed to mark the version and variant, so a valid v4 UUID always has a "4" and an "8/9/a/b" in specific positions — this tool sets those automatically.

Are the UUIDs generated here actually random?

Yes. They come from crypto.randomUUID() where the browser supports it, or crypto.getRandomValues() otherwise — the same cryptographically secure source used for encryption keys, not Math.random(), which is predictable.

Can two UUIDs ever collide?

With 122 random bits, the odds are astronomically small — you would need to generate billions of v4 UUIDs per second for decades before expecting a single collision.

Is anything I paste here sent to a server?

No. The whole tool is JavaScript running in your browser, and this site has no endpoint that accepts text. That matters when what you are pasting is a real API payload, a customer record, or a password.

Why is bulk generation capped at 100?

A hundred IDs is enough to seed a test fixture or fill a small batch import without turning this page into a data-export tool. If you need thousands, generate in a few rounds and copy each batch.

What is the difference between UUID and GUID?

Nothing practical — GUID is simply Microsoft's name for the same 128-bit identifier format. Every UUID this tool produces works anywhere a GUID is expected.

Related tools

Bookmark this page — the tool keeps working offline, and your settings stay in this browser. Built by Dynamb Technologies, who make software for a living.