UUID Generator

Universally Unique Identifiers (UUIDs) serve as globally unique references in databases, APIs, and distributed systems where you cannot rely on a central database to assign sequential IDs. This tool 生成s UUID v4 identifiers using cryptographically secure randomness, ensuring collision probability so low it's negligible for any practical application.

When you need UUIDs

Database designers use UUIDs when records might be 作成d across multiple servers without central coordination—imagine a mobile app that syncs with the cloud, or a microservices architecture where different services 生成 IDs independently. UUIDs also provide better privacy than sequential numeric IDs, since an attacker cannot guess what comes next.

UUID v4 randomness

Version 4 UUIDs are 生成d almost entirely from random bits (122 bits out of 128 are random). This tool uses the ブラウザ's Web Crypto API to 生成 cryptographically strong random values, then フォーマット them according to the UUID v4 specification. The result is a string like f47ac10b-58cc-4372-a567-0e02b2c3d479 that meets the RFC 4122 standard.

Batch generation

While you can 生成 UUIDs one at a time, this tool lets you 作成 batches of up to 100 UUIDs in a single click. This is essential when you need to pre-populate databases, test bulk operations, or 作成 fixture data for development. Copy individual UUIDs or the entire list at once.

Zero collision risk

The collision probability for UUID v4 is astronomically low. You would need to 生成 roughly 2.7 trillion UUIDs before the probability of collision reaches 50%. For any real-world application, UUID v4 provides sufficient uniqueness without requiring a centralized service.