🆔UUID v4 Generator
Generate multiple cryptographically secure UUID v4s at once. Supports hyphen and uppercase options. Useful for database primary keys, API identifiers, temporary tokens, tracking IDs, and avoiding filename collisions.
How to use
- 1Enter how many to generate.
- 2Choose options (hyphen / uppercase).
- 3Use the copy button to grab the result.
FAQ
Is UUID v4 really unique?+
Mathematically 122 bits of randomness — collision probability is negligible. Uses a safe random source (Web Crypto).
Compared to v1/v3/v5/v7?+
v4 is pure random. v1 is time + MAC; v7 is time + random (sortable). For general use, v4 is most common.
Downsides of UUID as DB primary key?+
Bigger than integer keys (16 bytes) and slightly slower index scans. Best for large distributed systems and microservices.
Can I use it as a security token?+
v4 uses safe randomness, so yes. For shorter tokens, try the Random String tool.
Why remove hyphens?+
Shorter URL use, more efficient when stored as BINARY(16) in databases, etc.
How many can I generate at once?+
No technical limit, but typically 1–1000. For very large quantities, prefer server-side batch generation.