UUID generator
Make UUIDs (v4 or v7) in bulk. Switch to uppercase, no hyphens, or { } braces.
Generated UUIDs
Choose version and format
Version
Fully random and the most widely used kind of UUID. Pick this if you're not sure.
From 1 to 1,000.
UUIDs are made on this device. They're never sent anywhere or saved.
Only your version, count and format settings are remembered on this device.
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Something not working, or an idea to make it better?
How to use
1. Choose the version and count
Below the list, under “Version”, tap “v4 random” or “v7 time-based”, then type a number in the “How many” box (1 to 1000). The list above is remade as soon as you change anything.
On the right, under “Version”, click “v4 random” or “v7 time-based”, then type a number in the “How many” box (1 to 1000). The list on the left is remade as soon as you change anything.
2. Choose the format
Under “Format”, turn “Uppercase”, “Remove hyphens (-)” and “Wrap in { }” on or off. The UUIDs above stay the same; only the way they're written changes.
On the right, under “Format”, turn “Uppercase”, “Remove hyphens (-)” and “Wrap in { }” on or off. The UUIDs on the left stay the same; only the way they're written changes.
3. Copy or save
Tap the copy icon to the right of a UUID to copy just that one. Tap “Copy all” to copy them all at once, one per line. Tap “Save as file” to save them as a text file (.txt).
In the list on the left, click the copy icon to the right of a UUID to copy just that one. Click “Copy all” to copy them all at once, one per line. Click “Save as file” to save them as a text file (.txt).
Great for
Writing test data by hand
Make as many IDs as you need for SQL INSERT statements or sample JSON. “Copy all” gives you one per line, ready to paste.
Developers and testers
Picking a database primary key
v7 starts with a timestamp, so new keys sort in creation order and keep indexes tidy. Compare it side by side with v4 to see what the values look like.
People designing databases
Matching a GUID format
Just switch uppercase, no hyphens and { } braces to get exactly the form the Windows Registry, C# or a config file expects.
Windows and .NET developers
Handing out lots of IDs at once
Make up to 1000 at a time and save them as a text file. Paste them into a spreadsheet to assign IDs to devices or members.
System admins and data staff
Good to know
- Generated UUIDs aren't saved. Copy the ones you need or save them to a file before closing the page.
- A UUID is a unique ID, not a secret. Don't use it in place of a password or a key that must stay private (use the Password generator instead).
- It makes v4 and v7 only. It can't make name-based v3 or v5, or v1, which uses device information.
About UUID v4 and v7
A UUID (also called a GUID) is a 128-bit ID written as 32 hexadecimal digits in an 8-4-4-4-12 pattern. Values made on different devices don't collide, without checking with any central server, so UUIDs are widely used for database keys, file names, API request IDs and more. In v4, all 122 bits except the 6 that mark the version and variant are random. It's the most common kind.
v7 is a newer kind defined in RFC 9562 in 2024. Its first 48 bits hold the time it was made, in milliseconds. Because v7 UUIDs sort in creation order, they stay tidy in database indexes and can be used to sort by time. This tool uses the browser's built-in cryptographic random numbers (crypto.getRandomValues), and when it makes many v7 UUIDs at once, it keeps them in creation order even within the same millisecond.
FAQ
Answers to common questions before you start.
Are the UUIDs sent anywhere?
No. UUIDs are made only inside the browser on your device. They're never sent to a server or recorded. Once the page has loaded, it works even offline.
Can two UUIDs ever be the same?
Not in practice. v4 has 122 random bits, so you'd have to make about 2.7 billion billion (2.7×10¹⁸) of them before the chance of a duplicate reached 50%. v7 also includes the time, so UUIDs made at different times never collide.
Should I choose v4 or v7?
If you're not sure, choose v4. v7 is better for database primary keys or when you want IDs to sort in creation order. Since anyone can read the creation time from a v7 UUID, use v4 for IDs where you don't want to reveal when they were made.
Are UUIDs and GUIDs different?
They're the same thing. GUID is Microsoft's name for it, and on Windows and .NET it's often written in uppercase and wrapped in “{ }”. Turn on “Uppercase” and “Wrap in { }” under “Format” to get that style.
Is it still the same UUID without hyphens or in uppercase?
Yes. UUID hex digits aren't case-sensitive, and the hyphens are just separators for readability. Some systems only accept a specific form, though, so follow the rules of the system you're using.
Can I tell when a v7 UUID was made?
Yes. The first 12 hex digits (ignoring hyphens) are the number of milliseconds since January 1, 1970, in hexadecimal. When you choose v7, this tool shows that time above the list.
How many can I make at once?
From 1 to 1000. When there are many, scroll through the list to see them all. “Copy all” and “Save as file” put one per line.
Can I use one as a password?
We don't recommend it. A UUID is designed to be unique, not secret, and the time part of a v7 UUID can be guessed. For passwords and secret keys, use a value made with the Password generator.
Are my settings remembered?
Yes. The version, count and format are remembered in this device's browser, so they're ready the next time you open the page. The UUIDs themselves aren't saved.
Is it free?
Yes, it's free. No sign-up and no ads.
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