UUID Generator

What is a v4 UUID?

A universally unique identifier is a 128-bit value written as 32 hex digits in the pattern 8-4-4-4-12. Version 4 fills it with random bits (except the version and variant markers), making collisions astronomically unlikely — handy for IDs, keys, and filenames.

Random quality

These use crypto.randomUUID() / crypto.getRandomValues — the browser's cryptographically secure generator — not Math.random.

Privacy

Generated locally; nothing is uploaded.

Frequently asked questions

Are these safe as unique identifiers?

Yes. Version-4 UUIDs use 122 random bits from the browser's cryptographic RNG, so collisions are astronomically unlikely across any realistic number of IDs.

Can I use them as security tokens?

They're unpredictable, but for authentication prefer a purpose-built secret. UUIDs are ideal for IDs, keys and filenames.

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