UUID Generator

Runs entirely in your browser

Generate random, RFC 4122-compliant UUID v4 identifiers directly in your browser.

How many UUIDs?

Up to 1000 at a time.

Uppercase Include hyphens

Generated UUIDs

What is UUID Generator?

UUID Generator creates version 4 Universally Unique Identifiers — 128-bit values commonly used as database keys, request IDs, session tokens and object identifiers where you need a unique value without a central authority assigning it.

How to use UUID Generator

Choose how many UUIDs you need.
Optionally toggle uppercase or remove hyphens.
Click Generate, then copy the results.

Features

Generates RFC 4122-compliant UUID v4 values.
Generate up to 1000 UUIDs at once, one per line.
Uses a cryptographically secure random source, not Math.random().
100% client-side — nothing is sent to a server.

Things to know about this generator

When crypto.randomUUID() is available in your browser, this tool uses it directly. Otherwise it falls back to filling 16 bytes with crypto.getRandomValues() and manually setting the version (0x40) and variant (0x80) bits per RFC 4122 — both paths use the same cryptographically secure source, never Math.random().
The Uppercase and Include hyphens toggles only reformat the string after it's generated — they don't add or remove any of the 122 random bits, so a hyphen-free lowercase UUID and its uppercase, hyphenated equivalent are equally unpredictable.
Asking for more than 1000 at once doesn't error — the quantity is silently clamped to 1000 and a status message tells you it was limited.
UUID v4 has no built-in ordering: two IDs generated seconds apart look completely unrelated. If you need identifiers that sort roughly by creation time (for database index locality, for example), a v4 UUID isn't the right tool — that requires a time-based scheme like UUID v1 or v7, which this generator doesn't produce.

Is UUID Generator safe?

Yes. UUID Generator produces every ID locally using the Web Crypto API's cryptographically secure random source — crypto.randomUUID(), or manually set version/variant bits over crypto.getRandomValues() as a fallback — so nothing is sent to a server, and since a random UUID carries no personal data, no account is needed either way.

Frequently Asked Questions

What UUID version does this generate?

UUID version 4 — randomly generated identifiers, the most common type used in application code and databases.

How random are these UUIDs?

They're generated with the browser's crypto.getRandomValues() API (falling back to crypto.randomUUID() where available), which is cryptographically strong — not Math.random().

Can two generated UUIDs collide?

In practice, no. UUID v4 has 122 random bits, so the chance of any collision is astronomically small even across billions of generated IDs.