FREE TOOL

UUID Generator

Generate up to 100 UUID v4 or v7 values, format, validate, copy, and download them.

Loading tool…

About UUID Generator

Generate up to 100 RFC 9562 UUID v4 or v7 values locally in your browser. Choose uppercase or lowercase and optional hyphens, then copy all or download TXT and JSON. You can also validate an existing UUID.

How to use

1.Choose the quantity, UUID version, case, and hyphen format.
2.Generate and review the values.
3.Copy all or download TXT or JSON, and use the validator for existing UUIDs.

Useful for

Creating database identifiers in bulk
Creating time-sortable UUID v7 values
Preparing API and mock data
Validating received UUIDs

Verified examples and scope

These examples describe reproducible behavior in this tool. They are not a guarantee for inputs outside the documented scope.

Input or setting	Expected result	Condition
v4, one value, lowercase, hyphens enabled	One value matching xxxxxxxx-xxxx-4xxx-[89ab]xxx-xxxxxxxxxxxx	The hexadecimal x positions vary on every run.
v7, 100 values, uppercase, no hyphens	One hundred 32-character uppercase hexadecimal values	Display formatting preserves the UUID version and variant bits.

Known limitations

Generation is limited to 1–100 values, and validation accepts UUID v4 and v7.
The tool cannot guarantee zero collisions or strict generation order within the same millisecond for v7.

If the result is unexpected

A failed validation should be checked for 32 hexadecimal digits, version 4 or 7, and the RFC variant.

How it works

v4 uses crypto.randomUUID or crypto.getRandomValues; v7 places the millisecond timestamp in the first 48 bits.

The version and variant layout follows RFC 9562 UUID v4 and v7.

UUID generation and validation run in the browser.

Input examples

Generate 100 UUID v7 database IDs
Download UUID v4 API test data as JSON

Notes and limitations

UUID v4 and v7 follow RFC 9562. Version 7 includes generation time but is not a strict sequence.
Collision probability is extremely low, but uniqueness is not a mathematical guarantee.

Frequently asked questions

What is the difference between UUID v4 and v7?

UUID v4 is primarily random. UUID v7 starts with a Unix timestamp in milliseconds, making values easier to sort chronologically.

Which specification does this tool follow?

Generation and validation follow RFC 9562, which defines UUID versions 4 and 7.

Are uppercase or hyphen-free UUIDs valid?

The tool can format them that way for display or integration. Check the exact accepted format of the system receiving the value.

Can two generated UUIDs ever match?

The probability of a UUID v4 collision is extremely low, but uniqueness is not a mathematical guarantee.