UUID Generator
Generate one or many RFC-4122 v4 UUIDs, in standard, uppercase, or no-hyphen format.
Random RFC-4122 v4 UUIDs, generated locally via the Web Crypto API.
About this tool
A UUID (Universally Unique Identifier), also called a GUID, is a 128-bit value used as a primary key, correlation id, file name, or any identifier that must be unique without a central authority. This generator produces RFC 4122 version 4 UUIDs, whose bits are almost entirely random, making accidental collisions astronomically unlikely.
You can generate a single UUID or a whole batch at once, and format them to fit your context — standard lowercase with hyphens, uppercase, or with the hyphens removed for compact storage. Generation happens in your browser, so the identifiers are yours alone and are never recorded anywhere.
How to use
- Choose how many UUIDs you want to generate in one go.
- Pick a format: standard (lowercase with hyphens), uppercase, or no-hyphen.
- Generate to produce the identifiers instantly.
- Copy a single UUID or the entire list to your clipboard.
- Paste them into your database seed, config, code, or test data.
- Regenerate whenever you need a fresh set.
Features
- Produces RFC 4122 version 4 UUIDs with strong randomness for negligible collision risk.
- Bulk generation so you can create many identifiers in a single click.
- Three output formats: standard hyphenated, uppercase, and hyphen-free.
- One-click copy for a single value or the whole batch.
- Perfect for database primary keys, request correlation ids, and unique file names.
- Runs completely client-side, so generated UUIDs are never logged or transmitted.
Frequently asked questions
What kind of UUID does this generate?
It generates version 4 UUIDs as defined by RFC 4122, where almost all bits are random. This is the most common variant for general-purpose unique identifiers.
Are the UUIDs stored or sent to a server?
No. Each UUID is generated in your browser and nothing is uploaded or logged. The identifiers exist only where you paste them.
How likely are two UUIDs to collide?
A version 4 UUID has 122 random bits, so the chance of generating the same one twice is negligible in practice. You would need to generate an enormous number before a collision became remotely plausible.
What is the difference between UUID and GUID?
They refer to the same thing. GUID is Microsoft's term for the same 128-bit identifier standard; UUID is the more common cross-platform name.
Why would I remove the hyphens?
Some systems, URLs, or database columns are more compact without hyphens. The no-hyphen format gives you a 32-character string that is easy to store or embed while representing the same value.