UUID Generator
Generate cryptographically random version-4 UUIDs (GUIDs) in bulk. Everything runs in your browser using the Web Crypto API.
How to Use UUID Generator
To generate UUIDs, select the UUID version (v4 for random, or nil for the zero UUID), choose how many UUIDs to generate, and pick your preferred format (standard lowercase, uppercase, or without hyphens). Click Generate and the UUIDs appear in the output area instantly.
Click Copy to copy all generated UUIDs to your clipboard. UUID v4 generates random unique identifiers suitable for use as database primary keys, session tokens, file names, and any context requiring a unique identifier with no central coordination.
Frequently Asked Questions
What is a UUID? expand_more
A UUID (Universally Unique Identifier) is a 128-bit number used to uniquely identify objects or records across systems. It is formatted as 32 hexadecimal digits in groups separated by hyphens: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx.
What is the difference between UUID v1, v4, and v5? expand_more
UUID v1 is based on timestamp and MAC address. UUID v4 is randomly generated and the most commonly used. UUID v5 is namespace-based using SHA-1 hashing. This tool generates UUID v4.
Are UUID v4 values truly unique? expand_more
UUID v4 values are random 122-bit numbers. The probability of two random UUIDs colliding is astronomically small — approximately 1 in 5.3 × 10³⁶. For practical purposes they are universally unique.
What is the nil UUID? expand_more
The nil UUID (all zeros: 00000000-0000-0000-0000-000000000000) is a special-case UUID used as a placeholder or default null value in systems that require a UUID format but want to indicate 'no value'.
Can I use UUIDs as database primary keys? expand_more
Yes. UUIDs are widely used as primary keys in distributed systems because they can be generated by clients without central coordination and are unique across systems without risking collisions.
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