Toolstia / UUID generator
Generate UUIDs
A UUID is a 128-bit identifier written as 32 hexadecimal digits, such as 3f2504e0-4f89-41d3-9a0c-0305e82c3301. Generate up to 100 random version 4 UUIDs and copy them all at once.
Made in your browser with its secure random generator. Nothing is sent or stored.
How it works
- Choose how many you want.
- Pick upper case or hyphen-free formats if you need them.
- Copy the list.
What version 4 means
Version 4 UUIDs are made from random numbers. Six of the 128 bits are fixed to mark the version and variant, leaving 122 random bits.
Can two be the same?
In practice no. The chance of a collision among random 122-bit values is so small that systems treat them as unique without checking.
Random source
The numbers come from your browser's secure random generator, the same kind used for cryptography, not from Math.random.
When not to use them
UUIDs are identifiers, not secrets. Do not use one as a password or access token on its own. Random v4 UUIDs also index less efficiently in some databases than sequential IDs.
Questions
Are the UUIDs stored or sent anywhere?
No. They are made in your browser and disappear when you leave the page.
What is the difference between a UUID and a GUID?
They are the same format. GUID is the name Microsoft uses.
Can I get other versions?
Not yet. This tool makes version 4 UUIDs only.