UUID Generator
Generate random version-4 UUIDs instantly.
How to use
Enter your values and pick a mode if the tool offers one.
Click calculate — results appear instantly, computed in your browser.
Copy the result or save the tool to your favorites.
Frequently asked questions
A universally unique identifier — a 128-bit value used to label things uniquely.
Version 4, which is randomly generated.
Collisions are astronomically unlikely with random v4 UUIDs.
Yes — in your browser using cryptographic randomness.
Yes, set the count up to 100.
About the UUID Generator
This tool generates version 4 UUIDs, the random universally unique identifiers used throughout software to label things without coordination. Generate one or many at once, each produced locally in your browser using secure randomness.
What a UUID is
A UUID, or universally unique identifier, is a 128-bit value usually written as 32 hexadecimal digits in five groups separated by hyphens, such as 550e8400-e29b-41d4-a716-446655440000. Its purpose is to give something a name that is unique without any central authority handing out numbers. Two different systems, with no knowledge of each other, can each generate UUIDs and trust that they will not collide, which is enormously useful in distributed software.
Why collisions are practically impossible
A version 4 UUID is almost entirely random, with 122 bits of randomness. That produces a number of possible values so vast that the chance of two randomly generated UUIDs matching is negligible even across billions of them. To put it in perspective, you would need to generate UUIDs continuously for longer than a human lifetime before a collision became remotely likely. This is why developers treat them as safe to use as unique keys without checking for duplicates.
Where UUIDs are used
UUIDs appear as database primary keys, especially in systems that need to generate records on many servers without coordinating; as identifiers in APIs and message queues; as keys for files, sessions, and transactions; and anywhere a unique label is needed before a central database can assign one. Their independence from any counter or sequence is precisely what makes them valuable in modern, distributed architectures.
UUID versions
There are several UUID versions. Version 4 is random, version 1 is based on time and the machine's network address, and others derive from names or hashes. Version 4 is the most common general-purpose choice because it requires no inputs and leaks no information about when or where it was created, unlike time-based versions. This tool generates version 4 specifically.
Privacy and related tools
UUIDs are generated on your device using cryptographic randomness and are never transmitted or stored, so they are genuinely yours. You can generate up to a hundred at once for seeding data or testing. For random passwords see the Strong Password Generator, and for encoding data the Base64 Encoder / Decoder. Generation is instant.