About the UUID Generator
Tezmy's UUID Generator creates universally unique identifiers using your browser's secure random number generator. Choose version 4 for fully random IDs, or version 7 for IDs that start with a timestamp and sort in creation order, which makes them great as database keys. Make up to 1,000 at a time, switch to uppercase, remove hyphens or add braces for Microsoft-style GUIDs, then copy them or download a text file.
Updated October 2026
How to use the UUID Generator
- 1Choose v4 (random) or v7 (time-ordered).
- 2Enter how many UUIDs you need.
- 3Pick uppercase, hyphens or braces if needed.
- 4Copy them all or download a .txt file.
Where UUIDs are used
- Primary keys in databases, especially across several servers.
- IDs for files, uploads, orders and API resources.
- Session and request IDs in logs.
- Test data and mock records.
v4 or v7?
Version 4 UUIDs are completely random, so they reveal nothing about when they were made. Version 7 UUIDs start with a timestamp, so new IDs sort after older ones; databases can index them faster, making v7 a great choice for primary keys. Both are unique for all practical purposes.
Formats for every system
Standard UUIDs are lowercase with hyphens, like 3f2b8c6e-…. Some systems want uppercase, no hyphens (32 characters) or braces {…} as used for Microsoft GUIDs. Choose the format before generating, then copy all or download them as a text file.
Generated securely
Every UUID uses your browser's cryptographically secure random number generator, and they're created on your own device, so no list of your IDs exists anywhere else. You can make up to 1,000 at once.
How unique are UUIDs?
A version 4 UUID has 122 random bits, which is about 5.3 undecillion possible values. You could generate a billion UUIDs every second for decades and the chance of a single duplicate would still be tiny. That's why systems can create IDs independently without checking with each other.
Generate UUIDs on any device
Everything runs in your own browser, so nothing you paste is uploaded or logged. It works on phones, tablets and computers with nothing to install, and there's no sign-up. If you need a fingerprint instead, use the Hash Generator, and the Random Number Generator makes plain numbers.
Features
- UUID v4 and v7
- Up to 1,000 at once
- Cryptographically secure randomness
- Uppercase, no hyphens and braces
- Copy all or download
- Generated in your browser
Frequently asked questions
What is a UUID?
A UUID (universally unique identifier) is a 128-bit ID written as 32 hex digits, like 3f2b8c9e-4d1a-4b7e-9c2f-8a1d6e5b4c3a. They're so unlikely to repeat that systems can create them independently without checking a central list.
What's the difference between UUID and GUID?
They're the same thing. GUID (globally unique identifier) is Microsoft's name for a UUID, often written in uppercase with curly braces.
Should I use v4 or v7?
Use v4 when you just need a random, unguessable ID. Use v7 for database primary keys: because they start with the time, new IDs sort in order and keep indexes fast.
Can two UUIDs ever be the same?
In theory yes, but with v4's 122 random bits you'd need to generate billions per second for many years to have a realistic chance of a duplicate.
Are these UUIDs secure?
They use the Web Crypto API's secure random numbers. Still, UUIDs are identifiers, not passwords, so don't rely on them alone as secret tokens.
How many UUIDs can I generate at once?
Up to 1,000. Download them as a text file for bulk use.
Should I use UUIDs as passwords?
No. Use the Password Generator for passwords; UUIDs are identifiers and follow a fixed format.
Is it free?
Yes. Free, no sign-up, unlimited use.
Can I generate UUIDs without hyphens?
Yes. Turn off hyphens to get 32-character IDs, handy for some databases and file names.
Does it work on my phone?
Yes. Generate, copy or download UUIDs in any mobile browser.