UUID Generator

Random and time-ordered IDs on demand

Generate cryptographically-random UUID v4, time-ordered UUID v7 and NIL identifiers in bulk, with uppercase, no-hyphen and brace formats, copy or download them in one click.

A UUID (Universally Unique Identifier) is a 128-bit value used to label database rows, API resources, files and messages without a central authority handing out numbers. This generator creates version-4 UUIDs, whose bits are almost entirely random, plus modern version-7 UUIDs that embed a millisecond timestamp so they sort chronologically, ideal as database primary keys. It uses your browser's cryptographically secure random number generator, so collisions are effectively impossible.

Features

UUID v4 (random) and v7 (time-ordered) versions
NIL UUID plus bulk generation up to 1000
Cryptographically secure randomness
Uppercase, no-hyphen and brace (GUID) formats
Copy all or download as a .txt file
Runs locally: no server calls, no signup

How to use UUID Generator

1
Set the amount
Choose how many UUIDs you need.
2
Pick a format
Toggle uppercase, no hyphens or braces.
3
Generate
Click generate for a fresh batch.
4
Copy
Copy all UUIDs to your clipboard.

Common use cases

Seed database primary keys
Create unique API request IDs
Generate test fixtures and mock data
Produce idempotency keys

Detailed guide

Format them the way your code expects

Need them uppercase for a legacy system, stripped of hyphens for a compact key, or wrapped in braces like a Windows GUID? Toggle the options and every UUID reformats instantly. Switch between v4, v7 and the all-zero NIL UUID, generate up to a thousand at a time, and copy the whole list or download it as a text file. Everything happens locally, so nothing is ever transmitted.

UUID versions explained

A UUID is a 128-bit identifier written as 32 hexadecimal digits in five groups, like 550e8400-e29b-41d4-a716-446655440000. Version 4 fills almost all of those bits with random data, so it's the default choice when you just need a unique ID. Version 7, standardised in RFC 9562 in 2024, puts a Unix timestamp in the first 48 bits and fills the rest with random data, so the IDs sort in creation order. The nil UUID is all zeros and is used as an empty placeholder. The version number appears as the first digit of the third group.

Collisions and database performance

Random v4 UUIDs have 122 random bits, so collisions are practically impossible: you would need to generate about a billion per second for around 85 years to reach a 50% chance of a single duplicate. For database primary keys, v7 is often the better choice, because time-ordered IDs are inserted at the end of an index instead of at random positions, which reduces page splits and keeps inserts fast in PostgreSQL and MySQL. UUIDs here are generated with your browser's cryptographically secure random number generator.

Frequently asked questions

What is a UUID v4?

A version-4 UUID is a 128-bit identifier whose bits are almost all random. It's the most common UUID type because it needs no central coordination and has a negligible chance of collision.

Are these UUIDs truly random and safe to use?

Yes. They're generated with your browser's cryptographically secure random source (crypto.randomUUID or crypto.getRandomValues), which is suitable for identifiers.

Can I generate many at once?

Yes: create up to 1,000 UUIDs in a single batch and copy them all with one click.

Is anything sent to a server?

No. All generation happens locally in your browser, so your identifiers never leave your device.

How do I generate a UUID v4 online?

Click generate to get a random RFC 4122 version-4 UUID instantly. Set a count to produce many at once (hundreds or thousands), and copy them individually or in bulk. Everything is generated in your browser.

What is the difference between UUID v1, v4 and v7?

v1 is timestamp-and-MAC based, v4 is fully random (the most common), and v7 is time-ordered random, which sorts chronologically and is great as a database key. The generator supports these versions.

Are the UUIDs generated privately in my browser?

Yes. They are created locally using the browser's secure random source and are never sent to a server, so they are safe to use as real identifiers.

Random and time-ordered IDs on demand

Features

How to use UUID Generator

Set the amount

Pick a format

Generate

Copy

Common use cases