UUIDジェネレーター

What this tool does

Create random UUID version 4 values, from 1 to 100 at a time. Test data and temporary record IDs are the usual reason to generate a batch. These are not sequential keys and not passwords, and the page cannot tell whether a value already exists in another system.

How to use

1. Choose how many UUID v4 values to generate, from 1 to 100.
2. Press Generate. Use Regenerate for a new set with the same count.
3. Copy one value or copy all of them. Clear removes the list.

Examples

• One identifier

  A UUID v4 looks like 3f2504e0-4f89-41d3-9a0c-0305e82c3301, with version 4 in the third group.

• A batch

  Generating 10 values is useful for test data. Each value is created separately.

How it works

A UUID is a 128-bit identifier. Version 4 uses random bits, with a fixed version and variant. This tool uses crypto.randomUUID() when the browser provides it, or crypto.getRandomValues() otherwise. It does not use Math.random(). UUIDs are unique with extremely high probability, not a proof of identity or a secret.

Limitations

One click produces at most 100 values. They are random version-4 identifiers, not sequential keys and not a password. The page cannot tell you whether the same value already exists in another system.

See the disclaimer for what these tools do not cover.

FAQ

Is the UUID Generator free?

Yes. Creating UUID version 4 values in this browser is free, and you do not need an account.

Are these UUIDs uploaded?

No. Values are created in your browser and are not sent to a server.

Can I generate more than 100?

Not in one click. The limit keeps the page from filling with a huge list.

What is a UUID v4?

A UUID is a 128-bit identifier written as 36 characters, such as 123e4567-e89b-42d3-a456-426614174000. Version 4 fills almost all of those bits at random.

Can two random UUIDs be the same?

In theory, yes, but with 122 random bits the chance is so small that UUID v4 values are treated as unique in practice.