How to generate UUIDs
- Choose the version and how many UUIDs you need (up to 1,000).
- Pick the format: uppercase, without hyphens or wrapped in braces.
- Copy them or download them as a text file. Click Generate for a new set.
UUID v4 or v7?
- Version 4 is made of 122 random bits. It is the most widely used kind and works everywhere a UUID or GUID is accepted.
- Version 7 (RFC 9562) starts with the current time in milliseconds, so new IDs sort after older ones. This keeps database indexes compact and fast, which makes v7 a good choice for primary keys.
FAQ
Can two UUIDs ever be the same?
In practice, no. With 122 random bits, you would need to generate billions of UUIDs every second for many years before a duplicate became likely. These UUIDs use your browser’s cryptographically secure random generator.
What is the difference between a UUID and a GUID?
None. GUID (globally unique identifier) is Microsoft’s name for the same 128-bit format, often written in uppercase and inside braces, like {3F2504E0-4F89-41D3-9A0C-0305E82C3301}.
Is a UUID secret?
No. A v4 UUID is hard to guess, but it is an identifier, not a password. A v7 UUID also reveals when it was created.