UUID v4 uses 122 bits of random numbers, making the theoretical collision probability extremely low. To achieve a 50% collision probability, you would need to generate approximately 2.71 × 10^18 UUIDs. In practice, collision risk can be safely ignored.

UUID Generator

Batch generate UUID v4 random identifiers with support for uppercase/lowercase and with/without hyphens formats.

Quantity

Uppercase With hyphens

FAQ

What is a UUID?
UUID (Universally Unique Identifier) is a 128-bit universal unique identifier. The standard format consists of 32 hexadecimal characters divided into 5 groups, such as 550E8400-E29B-41D4-A716-446655440000. UUID v4 is generated based on cryptographically secure random numbers with extremely low collision probability, widely used for database primary keys, session identifiers, file names, and more.

What's the difference between UUID v4 and v7?
UUID v4 is entirely based on random numbers without any time or space information. UUID v7 includes a timestamp prefix that allows sorting by generation time, making it more suitable for database indexing. This tool defaults to generating v4 version. If you need sortable identifiers, consider other options like ULID or Snowflake.

Related guide

UUID, QR Code and Base64: Where Three Generators Stop Telling You They Failed
The UUID page draws real entropy from crypto.getRandomValues, but its count box turns 0 and abc into ten and ignores your format checkboxes until you press Generate again. The QR generator has no error path: ask for more than the error-correction level can hold and it leaves you an invisible canvas that the Download button still exports as a 2,786-byte PNG. The Base64 page trusts your browser's MIME guess, never shows gigabytes, and marks its preview box ready for files it cannot preview. All figures measured by driving the pages.