UUID Generator
Create as many version 4 UUIDs as you need, with the version and variant bits set correctly. They come from the platform’s cryptographic random source rather than a general-purpose generator, so they are not predictable from an earlier one, and they are not sequential, so they do not reveal how many records exist.
Up to 1,000 at a time.
The canonical form is lower-case. Upper case is accepted by most systems, not all.
The braced form found in Microsoft tooling and in some configuration formats.
How uuid generator works
- Set the countOne identifier, or up to a thousand for seeding a database.
- GenerateSixteen bytes are drawn from the platform source, then the version and variant bits are set.
- Copy or downloadOne identifier per line, ready to paste or save as a file.
What you get
Generate random v4 UUIDs from the browser’s cryptographic source. Everything happens inside this page: the file is read by your browser, transformed in memory and handed straight back to you as a download. There is no upload queue, no waiting for a server, and nothing left behind when you close the tab.
Supported formats
This tool works on text you paste or type, so there is no file format to worry about. Nothing you type is sent anywhere.
Limitations, stated up front
- Generated values stay in the box until you clear it or reload. Furtu does not clear it for you, because doing so mid-copy is worse than the risk.
- A v4 identifier is an identifier, not a secret. Do not use one as a session token or an API key.
Frequently asked questions
Are these unique?
A v4 identifier carries 122 random bits, which is a one in a billion-billion-billion chance of a collision per pair. The format also fixes a version nibble and a variant nibble, so those bits are not random. For billions of records, collisions are not a practical concern; for the same reasons, do not use one where a secret is needed.
Why not sequential identifiers?
Sequential identifiers leak: the number of records you have, the order they were created, and how fast you are growing. A random identifier reveals none of that. It is also not sortable by time, which is sometimes what you want and sometimes not — an identifier with a timestamp prefix is the answer when order matters.
Where do the random numbers come from?
The platform’s cryptographic random source, which is designed for exactly this. Not the general-purpose pseudo-random generator built into the language, which is fast and fine for shuffling a list and entirely wrong for anything that must not be guessable.
What is the difference between v4 and v7?
A v4 is fully random. A v7 puts a millisecond timestamp in the high bits and random data in the rest, so the identifiers sort by creation time and are still unique. Furtu generates v4 because it is the one every system accepts; if you need time ordering, that is a deliberate choice with a different library.
Are the generated IDs uploaded or logged?
They come from your browser's own cryptographic random source, so nothing is uploaded and nothing is generated on a server that could see them or count them. Furtu has no record of how many you have made.