無料UUIDジェネレーターオンライン | Fairmont AI

UUIDをオンラインで無料生成。プロジェクト用のUUID v4値を単一またはバルクで作成。

Our free UUID Generator creates universally unique identifiers (UUID v4) instantly in your browser. UUIDs are 128-bit identifiers used extensively in software development to uniquely identify objects, database records, API resources, and more. Generate a single UUID or up to 50 at once, then copy them individually or all at once. All generation happens client-side using your browser

How to Generate UUIDs

  1. Set the Count: Enter how many UUIDs you need, from 1 to 50. The default is 5.
  2. Click Generate: Click the Generate button to instantly create your UUID v4 values using a cryptographically secure random generator.
  3. Copy Your UUIDs: Hover over any UUID and click the copy icon to copy it individually, or use 'Copy All' to get all UUIDs at once as newline-separated values.

Frequently Asked Questions

What is a UUID?

A UUID (Universally Unique Identifier) is a 128-bit label used to uniquely identify information in computer systems. The standard format is 8-4-4-4-12 hexadecimal digits, e.g., 550e8400-e29b-41d4-a716-446655440000.

What is UUID v4?

UUID v4 is generated using random numbers. It's the most commonly used version because it doesn't require any input beyond randomness, making it simple and safe to generate.

How unique is a UUID?

The probability of generating two identical UUID v4s is astronomically small — approximately 1 in 2^122. In practice, UUIDs are treated as unique.

Are these UUIDs safe to use in production?

Yes. Our generator uses crypto.randomUUID() which is cryptographically secure. These UUIDs are safe for production use in databases, APIs, and distributed systems.

Can I use UUIDs as database primary keys?

Yes, this is a very common use case. UUIDs as primary keys work great in distributed systems because they can be generated without a central database.

What are the other UUID versions?

UUID v1 is time-based, v2 is DCE security, v3 is name-based with MD5, v4 is random, and v5 is name-based with SHA-1. v4 and v7 are the most popular today.

Is UUID the same as GUID?

GUID (Globally Unique Identifier) is Microsoft's implementation of UUID. They are functionally identical and follow the same format.

Can I generate uppercase UUIDs?

UUIDs are typically displayed in lowercase as per the RFC standard. If you need uppercase, copy the UUID and use a text case converter.