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UUID Generator

Generate version 4 UUIDs in bulk from the browser's cryptographic random number generator.

UUID Generator

Generate random Version 4 UUIDs.

What UUID Generator does

A version 4 UUID is 122 random bits formatted as 36 characters. Its purpose is to let independent systems create identifiers that will not collide without asking a central authority for the next number.

Because they are random rather than sequential, they can be generated offline, in parallel, and by clients that have never spoken to each other.

  • Generate up to 50 version 4 UUIDs at once
  • Copy a single identifier or the whole list
  • Randomness from the browser's cryptographic generator

How to use UUID Generator

  1. 1

    Set how many you need

    Choose a quantity and regenerate as often as you like.

  2. 2

    Copy what you need

    Copy one line, or copy the whole list as newline-separated values.

Limits and known behaviour

  • Version 4 only. Time-ordered variants such as version 1 and version 7, and name-based versions 3 and 5, are not offered.
  • Random UUIDs make poor primary keys in some databases, because their randomness scatters inserts across the index and hurts write performance. Time-ordered identifiers are the usual answer to that.
  • UUIDs are identifiers, not secrets. They are not unguessable enough to serve as security tokens on their own, and they frequently appear in logs and URLs.
  • They are stored as 36 characters unless your database has a native UUID type, which costs more space than an integer key.

Privacy and data handling

Runs entirely in your browser

  • Identifiers are generated in the page and are not transmitted or recorded.
  • Version 4 UUIDs contain no timestamp, MAC address or other device information — unlike version 1, which encodes both.

Site-wide data handling, including analytics and advertising, is described in the privacy policy.

Frequently asked questions

Can two UUIDs collide?

In principle yes, in practice no. With 122 random bits you would need to generate billions per second for decades before a collision became likely, assuming a sound random source.

Can I use a UUID as a security token?

Better not to. They are designed for uniqueness rather than unpredictability, they are routinely logged, and they often appear in URLs where they leak through referrer headers and analytics. Use a purpose-built random token instead.