UUID Generator

Generate random v4 or time-ordered v7 UUIDs on demand — one at a time or up to 1,000 at once, in lowercase or uppercase. Everything runs locally in your browser.

UUID Generator features

v4 and v7 versions

Switch between fully random v4 and time-ordered, sortable v7 UUIDs with a single toggle.

Cryptographic randomness

Random bits come from your browser's crypto RNG, not a weak pseudo-random source.

Bulk generation

Create anywhere from 1 to 1,000 UUIDs at once, each on its own line.

Sortable time-ordered IDs

v7 prefixes a 48-bit Unix-ms timestamp so IDs sort by creation time.

Lowercase or uppercase

Output UUIDs in lowercase or UPPERCASE to match your style or schema.

100% in-browser

Generation happens locally — no UUID is ever sent to a server.

Overview

A UUID (Universally Unique Identifier), also called a GUID, is a 128-bit value used to label things — database rows, files, sessions, API objects — without a central authority handing out IDs. It is written as 32 hexadecimal digits split into five groups, like f47ac10b-58cc-4372-a567-0e02b2c3d479. Because the space of possible values is enormous, two independently generated UUIDs are effectively guaranteed never to collide.

This tool generates UUIDs the moment you click Generate. You choose the version, how many to create with the Count field (1 to 1000), and whether the output is lowercase or UPPERCASE. Each result is printed on its own line, ready to copy.

Version 4 is fully random: every UUID is drawn from your browser's cryptographic random number generator (crypto.getRandomValues / crypto.randomUUID), with the version and variant bits fixed per the spec. It carries no meaning beyond uniqueness, which makes it the safe default when you just need an unpredictable identifier.

Version 7 embeds a 48-bit Unix-millisecond timestamp as its prefix, followed by random bits. Because the timestamp leads, v7 UUIDs sort roughly in the order they were created — newer values come after older ones. That makes v7 ideal as a database primary key, where time-ordered IDs keep index inserts efficient and let you sort records chronologically by ID alone.

How to use the UUID Generator

Pick a version with the toggle: v4 (random) for an unpredictable ID, or v7 (time) for a sortable, time-ordered one.
Enter how many UUIDs you want in the Count field (any number from 1 to 1000).
Choose lowercase or UPPERCASE in the Case select.
Click the Generate button to produce the UUIDs.
Read the results in the output panel — one UUID per line.
Copy the output to use the identifiers in your code, database, or config.

Good to know

A few things worth keeping in mind when using generated UUIDs:

v7 reveals creation time. Because v7 embeds a millisecond timestamp, anyone holding the ID can read roughly when it was created. Prefer v4 if the identifier must not leak timing information.
UUIDs are identifiers, not secrets. They are unpredictable enough to be hard to guess, but they are not a substitute for proper authentication tokens or cryptographic keys.
Uniqueness is statistical. Collisions are extraordinarily unlikely but not provably impossible, so safety-critical systems should still enforce a uniqueness constraint at the storage layer.

Private by design

Every byte you paste into the UUID Generator is processed locally in your browser. Formatly makes no network request with your data, logs nothing, and stores nothing on any server — so it is safe for API responses, tokens, configuration and other sensitive content. Your most recent input and theme are saved only in your own browser's local storage.

UUID Generator FAQ

Are the generated UUIDs private and safe to use?

Yes. Every UUID is generated entirely in your browser using the built-in crypto random number generator. Nothing is uploaded, logged, or sent to a server, so even the values you create never leave your device.

Does this UUID generator work offline?

Yes. Once the page has loaded, generation runs fully on your machine with no network calls. You can keep clicking Generate with your connection turned off.

What is the difference between v4 and v7 UUIDs?

v4 is completely random and carries no information beyond uniqueness — best when you want an unpredictable, opaque ID. v7 starts with a 48-bit Unix-millisecond timestamp, so the IDs are time-ordered and sortable. Use v7 when you want database keys that insert efficiently and sort chronologically.

How many UUIDs can I generate at once?

The Count field accepts any value from 1 to 1000. Values below 1 are treated as 1, and anything above 1000 is capped at 1000. Each UUID appears on its own line in the output.

Are these UUIDs guaranteed to be unique?

UUIDs are designed to be practically unique, not mathematically impossible to repeat. With 122 random bits, the odds of a v4 collision are astronomically small. v7 reduces collisions further by combining a timestamp with random bits, but neither version guarantees uniqueness in an absolute sense.

Can I get the UUIDs in uppercase?

Yes. Set the Case select to UPPERCASE before generating, and every UUID — including the hyphens — will be returned with hex digits in uppercase. Choose lowercase for the more common style.

Is a UUID the same as a GUID?

Effectively, yes. GUID (Globally Unique Identifier) is Microsoft's name for the same 128-bit standard. The format and uniqueness guarantees are identical, so a UUID generated here can be used anywhere a GUID is expected.