Generate random UUID v4 values instantly with this free UUID generator online. Create single or bulk UUIDs (up to 100), validate existing UUIDs, and copy or download results -- all processed in your browser with nothing sent to a server.
A UUID (Universally Unique Identifier) is a 128-bit value used to identify information across systems without coordination. Formatted as 32 hexadecimal digits in five groups separated by hyphens (e.g., 550e8400-e29b-41d4-a716-446655440000), UUIDs are widely used as database primary keys, API request identifiers, and session tokens. The v4 variant generated by this tool uses cryptographically secure random numbers, making collisions practically impossible.
UUID (Universally Unique Identifier) and GUID (Globally Unique Identifier) refer to the same concept. UUID is the term used in the RFC 4122 specification and is standard across most platforms. GUID is the term Microsoft uses in Windows and .NET. Both follow the same format and structure. This generator produces standard RFC 4122 v4 UUIDs that work everywhere GUIDs are expected.
UUID v4 values contain 122 random bits (6 bits are used for version and variant identifiers). This gives 5.3 x 10^36 possible combinations. To have a 50 percent chance of a collision, you would need to generate about 2.7 x 10^18 UUIDs -- roughly 2.7 quintillion. This tool uses the browser's crypto.getRandomValues API for cryptographically secure randomness, making the output suitable for security-sensitive applications.
Yes. This UUID generator runs entirely in your browser using the Web Crypto API (crypto.getRandomValues). No UUIDs are sent to a server, stored, or logged. The randomness source is the same one browsers use for TLS encryption, making it cryptographically secure. The generated UUIDs conform to RFC 4122 v4 and are suitable for database keys, distributed systems, and any production use case.