UUID Generator
Generate up to 100 random version 4 UUIDs at once, with uppercase and no-dash options. They are made in your browser with crypto.randomUUID().
Also searched as: guid generator · uuid v4 · random uuid · generate uuid
Updated November 6, 2026
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How to use it
- 1
Choose how many
Pick a count from 1 to 100.
- 2
Set the format
Uppercase or lowercase, with or without dashes.
- 3
Copy them
Press Generate, then Copy all.
Questions about uuid generator
Which UUID version is this?
Version 4, which is random. Each one is practically certain to be unique.
Are they truly random?
They use the browser’s secure random generator.
Is anything sent to a server?
No, the IDs are created on your device.
What a version 4 UUID is
A UUID, or universally unique identifier, is a 128-bit value written as 32 hexadecimal digits in five groups, such as 123e4567-e89b-42d3-a456-426614174000. In a version 4 UUID, 6 of the 128 bits mark the version and variant, and the other 122 are random. That is so many possible values that you would need to generate about 2.7 quintillion of them to have even a 50 percent chance of one duplicate.
This tool uses your browser’s crypto.randomUUID(), which draws on the same secure random source used for encryption. It only makes version 4. The table shows how the other common versions differ.
| Version | How it is made | Typical use |
|---|---|---|
| 1 | Timestamp plus a node identifier, often a network address | Time-ordered IDs, but they can reveal when and where they were made |
| 4 | Random (what this tool makes) | General-purpose unique IDs |
| 5 | A SHA-1 hash of a namespace and a name | The same input always gives the same ID |
| 7 | A Unix timestamp followed by random bits | Database keys that sort by creation time |
Using them well
The no-dash and uppercase options match formats that some systems expect, such as 32 plain hex characters. The content is identical and only the writing differs, so to convert back, add dashes after digits 8, 12, 16 and 20.
Treat a UUID as an identifier. It is hard to guess, but IDs end up in web addresses, logs and emails, so use a purpose-built secret or token when something needs to stay private. As database keys, random version 4 values spread new rows across an index, so time-ordered keys such as version 7 can be faster for very large tables.