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UUID Generator
Generate random version 4 UUIDs one at a time or in bulk, using secure browser randomness.
Click Generate to create version 4 UUIDs.
About this tool
A UUID (Universally Unique Identifier) is a 128-bit value used to label something uniquely without a central authority handing out IDs. This tool generates version 4 UUIDs - the random kind - using your browser's built-in cryptographic random number generator, so each one is effectively guaranteed never to collide with another.
What UUIDs are used for
- Database keys - primary keys that can be created on any client without coordinating with the server.
- Distributed systems - request IDs, event IDs, and trace IDs that stay unique across many machines.
- File & resource names - guaranteeing two uploads or records never clash.
- API tokens & correlation IDs - tagging items for logging and debugging.
About version 4 UUIDs
A v4 UUID looks like 3f2504e0-4f89-41d3-9a0c-0305e82c3301: 32 hexadecimal digits in five groups separated by hyphens. 122 of its bits are random, which is so large a space that the chance of generating the same one twice is negligible. Generate a single ID or a batch, then copy them individually or all at once.
Generation uses crypto.randomUUID() locally in your browser - the IDs are never sent to or recorded by any server.
Frequently asked questions
What is a UUID?
A UUID is a 128-bit Universally Unique Identifier. It lets you label records, files, or requests uniquely without a central system assigning IDs.
What version of UUID does this generate?
Version 4 - the random variant. 122 of its bits are randomly generated, so collisions are practically impossible.
Are these UUIDs truly random and safe to use?
Yes. They are produced by your browser's cryptographically secure random generator (crypto.randomUUID), the same source used for security-sensitive values.
Can two generated UUIDs ever be the same?
The probability is so small it can be ignored in practice - you would need to generate billions per second for many years to have a meaningful chance of a collision.
Are the UUIDs stored or sent anywhere?
No. They are generated locally in your browser and never leave your device.
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