Generate UUIDs in multiple formats (v1, v4, nil, max) instantly. Free online tool for developers.
Configure options and generate UUIDs...
Configure options and generate UUIDs...
A UUID (Universally Unique Identifier) is a 128-bit identifier that's designed to be unique across space and time. UUIDs are also known as GUIDs (Globally Unique Identifiers) and are used to uniquely identify information in computer systems.
The standard format for UUIDs is 8-4-4-4-12 hexadecimal digits, separated by hyphens, such as: 550e8400-e29b-41d4-a716-446655440000
Generated using random or pseudo-random numbers. This is the most common type and provides excellent uniqueness for most applications.
Example: 550e8400-e29b-41d4-a716-446655440000
Generated using the current timestamp and MAC address. Provides temporal ordering and guaranteed uniqueness within the same machine.
Example: 6ba7b810-9dad-11d1-80b4-00c04fd430c8
A special UUID consisting of all zeros. Often used as a placeholder or to represent "no identifier" in databases and APIs.
Example: 00000000-0000-0000-0000-000000000000
A special UUID consisting of all 'f' characters. Sometimes used for testing or as a maximum boundary value.
Example: ffffffff-ffff-ffff-ffff-ffffffffffff
Use UUIDs as primary keys in databases to ensure uniqueness across distributed systems and avoid conflicts during data migration.
Generate unique identifiers for API resources, ensuring no conflicts when multiple systems create resources simultaneously.
Create unique filenames for uploaded files, preventing overwrites and ensuring each file has a distinct identifier.
Generate unique session IDs for user authentication, ensuring security and preventing session hijacking.
UUID v4 has 2^122 possible combinations, making the probability of collision extremely low. For most applications, UUIDs can be considered practically unique.
Use UUID v1 when you need temporal ordering or guaranteed uniqueness on the same machine. Use UUID v4 for general-purpose unique identifiers where randomness is preferred.
UUIDs are not designed for security - they're designed for uniqueness. Don't use them as passwords or security tokens. For security, use proper cryptographic functions.
Yes! This tool works completely offline in your browser. No data is sent to any server, ensuring your privacy and allowing you to generate UUIDs without an internet connection.