# UUID Generator

Generate random v4 UUIDs or time ordered v7 UUIDs, up to 1000 at once. Made by your browser with crypto.getRandomValues, never sent anywhere.

Canonical page: https://filetity.com/uuid-generator

## Capabilities

- Free: Yes, with no watermark and no page limit.
- Account required: No. There is no account system.
- Processed on device: Yes. The file is read by your browser and never uploaded. There is no server to send it to.
- Formats: UUID version 4 and version 7. Output with or without hyphens, in lower or upper case, and optionally in braces.
- Limits: Up to 1000 at a time. More than that is a script's job rather than a web page's, and the page says so instead of freezing.
- Mobile: Yes, on any modern mobile browser. Large files are limited by the memory the phone gives the browser.
- Offline: Yes, once the page has loaded. The tool keeps working with no network connection.

## Questions

### What is a version 7 UUID and when should I use one?

It puts a millisecond timestamp in the first 48 bits, so v7 values sort in the order they were created, as text and as bytes. That matters when the UUID is a database primary key: random keys scatter inserts across the whole index and fragment it, while time ordered keys append to the end. It became an RFC in May 2024.

### Are these safe to use as secret tokens?

For a session token or a password reset link, use a purpose built token rather than a UUID. A v4 carries 122 random bits, which is plenty of entropy, but a v7 spends 48 of its bits on a timestamp anyone can read back, and UUIDs turn up in logs and URLs where secrets should not be.

### Is a GUID the same thing as a UUID?

Yes. GUID is Microsoft's name for it and UUID is the name in the RFC, and the two describe the same 128 bit value. The one difference you will meet is presentation: Microsoft tooling often writes them wrapped in braces and in capitals, which is why both are options here.

### Could this generate a UUID somebody else already has?

In practice no. A version 4 has 122 random bits, and you would need to generate around 2.7 quintillion of them before a collision became likely at all. The realistic failure is not the mathematics but a weak random source, which is why this uses the browser's cryptographic one.

### Why do all my version 7 UUIDs start with the same characters?

Because they were made in the same millisecond and share a timestamp, and that is the feature rather than a fault. Their leading characters will differ from ones you generate tomorrow, and the last 74 bits are still random, so they remain unique.

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