Free Online UUID Generator
Generate secure, random UUID v4 strings instantly with our free UUID generator. Copy single or bulk GUIDs directly in your browser. No signup required.
About UUID Generator
The Doffl UUID Generator creates standard, universally unique identifiers instantly in your web browser. Built for software engineers, database administrators, and QA testers, it provides a fast way to produce cryptographically strong identifiers for software applications, schemas, and test environments.
Because the tool executes entirely on your device using client-side JavaScript, your generated values remain private and are never sent across a network. Generate single identifiers or batches in seconds without downloading dependencies or creating an account.
Key features
- Generate standard RFC 4122 version 4 UUIDs
- Create single identifiers or batches in bulk
- Runs client-side in the browser for privacy
- One-click copy to clipboard functionality
- Toggle between uppercase and lowercase output
- Option to include or strip standard hyphens
How to use UUID Generator
- Select the number of UUIDs you need to generate.
- Configure formatting options such as uppercase letters or hyphenation.
- Click the Generate button to produce your identifiers.
- Copy the generated values directly to your clipboard.
Who is it for?
- Database engineers assigning primary keys in distributed systems
- Backend developers creating mock data and integration test suites
- API designers establishing transaction and idempotency keys
- QA testers verifying user onboarding and entity creation flows
Frequently asked questions
What is the difference between a UUID and a GUID?
UUID stands for Universally Unique Identifier, an open standard defined by RFC 4122. GUID stands for Globally Unique Identifier, which is Microsoft's implementation of the same standard. In practice, they refer to the same 128-bit identifier format.
Which UUID version does this tool generate?
This tool produces Version 4 UUIDs, which are generated using cryptographically strong pseudo-random numbers.
Is generating UUIDs in the browser secure?
Yes. The generator utilizes the native Web Cryptography API (crypto.getRandomValues) directly on your device, ensuring high randomness without exposing generated keys to a remote server.
Can two generated UUIDs ever collide?
While technically possible, the probability of a collision with UUID v4 is negligible due to the 122 random bits available, making accidental duplication practically impossible.
Is this UUID generator free to use?
Yes, this tool is completely free with no usage limits, installations, or registration required.