UUID Generator
This tool generates cryptographically random v4 UUIDs using your browser's built-in secure random number generator — one at a time, or in bulk for scripts, databases, and test data.
How it works
Press "Generate" for a single UUID, or switch to bulk mode to create up to 100 at once. Every UUID is built from cryptographically secure random bytes (via the Web Crypto API), not Math.random(), so it is safe to use as a unique identifier.
Tip
UUIDs are conventionally written in lowercase, but both cases are valid per the spec — use the uppercase toggle if your system expects capital letters.
Can two generated UUIDs ever collide?
In theory, yes — but a v4 UUID has 122 random bits, giving about 5.3 × 10^36 possible values. You would need to generate billions of UUIDs per second for billions of years before a collision became likely.
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