UUID Generator
Generate random version-4 UUIDs, one or many at a time.
About this tool
A UUID (universally unique identifier), also called a GUID, is a
128-bit value written as 32 hexadecimal digits in five groups, like
550e8400-e29b-41d4-a716-446655440000. This tool generates
fresh UUIDs on demand so you can drop a unique identifier straight into
your code, database or config.
The point of a UUID is that you can create one anywhere — on any machine, in any service, offline — without checking with a central authority, and still be confident it won't collide with one generated somewhere else. That property makes them the standard choice for database primary keys, distributed systems, message and request IDs, file and object names, and anywhere two independently running pieces of software need to mint identifiers that must never clash.
The most common version in use today is version 4, which is almost entirely random. The number of possible values is so large that the practical chance of generating the same v4 UUID twice is effectively zero, which is why developers rely on them instead of, say, auto-incrementing numbers that only stay unique within a single database.
Generation happens in your browser, so the identifiers are yours alone and nothing is sent to or logged by a server.
Frequently asked questions
- What's the difference between a UUID and a GUID?
- None that matters in practice. GUID is Microsoft's name for the same 128-bit identifier that the rest of the world calls a UUID. The format and behaviour are identical.
- Can two UUIDs ever be the same?
- In theory yes, in practice effectively never for version 4. The pool of possible values is so vast that a collision is astronomically unlikely, which is exactly why UUIDs are trusted as unique keys.
- Which version does this generate?
- Version 4 (random), the general-purpose default used for database keys and distributed identifiers. It doesn't encode a timestamp or your machine's identity, so it reveals nothing about where or when it was made.
- Are UUIDs case-sensitive?
- The hexadecimal digits are conventionally lowercase, but UUIDs are compared case-insensitively. Systems may store or display them upper- or lowercase; they refer to the same value either way.
- Is it safe to use a UUID as a secret?
- No. A UUID is an identifier, not a password. Don't rely on one being hard to guess for security — use a proper secret or token where secrecy matters.