What Is a UUID Generator?
A UUID Generator creates universally unique identifiers, 128-bit values written as 32 hexadecimal digits in a pattern such as 123e4567-e89b-42d3-a456-426614174000. A UUID is designed so that two systems can create identifiers at the same time, with no coordination, and still never collide in practice. That makes UUIDs a popular choice for database keys, API request IDs, file names and session tokens.
This UUID Generator offers two modern versions. Version 4 is completely random apart from a few bits that mark its version and variant, and it is the most widely used type. Version 7, defined in the updated UUID standard, starts with a 48-bit Unix timestamp in milliseconds followed by random data. Because of that prefix, version 7 values sort roughly in creation order, which keeps database indexes tidy and fast.
You can format the output with uppercase letters, without hyphens or wrapped in braces, as different systems expect. A validator lets you paste any UUID to confirm its structure, see its version and, for version 7, read the embedded timestamp.
How to Use the UUID Generator
- Select version 4 for random identifiers or version 7 for time-ordered identifiers.
- Enter how many UUIDs you need, from 1 to 100.
- Choose formatting options: uppercase, no hyphens or braces. The list updates immediately.
- Press Generate UUIDs for a fresh batch whenever you like.
- Use Copy All to put the list on your clipboard, or Download .txt to save it as a file.
- To check an existing identifier, paste it into the validator and read the result underneath.
Key Features of Our UUID Generator
- Version 4 random and version 7 time-ordered UUIDs
- Bulk generation of up to 100 identifiers at once
- Uppercase, hyphen-free and brace-wrapped output formats
- One-click copy and a plain text download
- Built-in validator that shows the version, variant and nil or max values
- Version 7 timestamps decoded to a readable date and time
- Uses crypto.randomUUID when available and a secure fallback otherwise
- Runs offline in your browser with no sign-up
Benefits of Using an Online UUID Generator
Sequential database IDs reveal how many records you have and are hard to merge when several systems create data independently. UUIDs avoid both problems because any service can mint a new ID without asking a central counter.
Choosing version 7 gives you the same uniqueness plus better database performance. Random version 4 keys scatter inserts across an index, while time-ordered keys append near the end and reduce page splits.
Your privacy comes first. The UUID Generator runs entirely in your web browser. Nothing you enter is sent to our servers, which keeps your data private and makes results appear instantly. See our Privacy Policy for details.
Common Use Cases for the UUID Generator
- Primary keys for databases and distributed systems
- Correlation IDs that trace a request through several services
- Unique file or upload names that cannot clash
- Idempotency keys for payment and order APIs
- Seed data and fixtures for automated tests
- Device, session and token identifiers
- Placeholder IDs while prototyping an app or writing documentation
- Replacing guessable numeric IDs in public URLs
Tips for Getting the Best Results
- Store UUIDs in a native uuid column type when your database supports it. It uses 16 bytes instead of 36 text characters.
- Choose version 7 for new database tables where insert performance matters, and version 4 when you want no information such as time embedded in the ID.
- Do not treat a UUID as a secret. It is unique, but unlike a random token generated for authentication it should not be your only protection.
- Keep one consistent text format across your systems, for example lowercase with hyphens, to avoid comparison bugs.
- When sorting version 7 IDs, remember that values created in the same millisecond are not guaranteed to be in order.
- Use the validator when you debug an integration to spot copy and paste errors such as a missing character.
UUID Generator FAQ
What is a UUID?
A UUID, also called a GUID, is a 128-bit identifier that is practically guaranteed to be unique. It is written as 32 hexadecimal digits in five groups separated by hyphens.
Can two UUIDs ever be the same?
In theory yes, but in practice no. A version 4 UUID has 122 random bits, so the chance of a duplicate is so small that you would need to create billions of IDs per second for many years to see one.
What is the difference between UUID v4 and v7?
Version 4 is entirely random. Version 7 begins with a millisecond timestamp, so IDs sort by creation time while staying unique. Both are valid standard UUIDs.
Is a UUID the same as a GUID?
Yes, for practical purposes. GUID is the term used by Microsoft, and the format is the same as a UUID.
Are these UUIDs safe to use in production?
Yes. They are generated with the browser's secure random source and follow the standard layout. For bulk server-side generation, use your language's UUID library.
Does this tool store the UUIDs I create?
No. They are created on your device and exist only on your screen until you copy or download them.