UUID Generator
Free online UUID/GUID generator tool (v4)
What is a UUID?
UUID (Universally Unique Identifier) is a 128-bit identifier that is unique across space and time without requiring a central coordinator. Version 4 UUIDs use random numbers and are the most common. UUIDs look like: 550e8400-e29b-41d4-a716-446655440000. They are used as database primary keys, file names, session IDs, and more.
How to Generate UUIDs
Click Generate to create random UUIDs (v4). Adjust the quantity, toggle uppercase or no-dashes options. Copy individual UUIDs or all at once.
▶How unique is a UUID v4?
UUID v4 uses 122 random bits, giving 2^122 possible values. The probability of generating a duplicate is negligibly small — you would need to generate billions per second for millions of years to have a reasonable chance of collision.
▶What is the difference between UUID and GUID?
GUID (Globally Unique Identifier) is Microsoft's name for UUID. They are the same thing. GUIDs are typically displayed with braces: {550e8400-e29b-41d4-a716-446655440000}.
▶Can UUIDs be guessed?
UUID v4 uses random numbers, making them impossible to predict without knowing the random number generator state. UUID v1 uses timestamps and MAC addresses, which may leak information.