UUID v4 Generator UUID v4 生成器 


          

            
            
            
          

        


        
        

          

            
What is UUID v4?

            
UUID (Universally Unique Identifier) is a 128-bit identifier standard defined by RFC 4122. Version 4 is generated entirely from random numbers, requiring no central authority. The format is 8-4-4-4-12 hexadecimal characters, e.g., 550e8400-e29b-41d4-a716-446655440000. With 122 effective random bits, the chance of collision is negligible even at massive scale — roughly one in 5.3 × 10³⁶.


            
Why Use UUID as a Primary Key?

            
UUIDs can be generated client-side without a database round-trip, which is ideal for distributed systems, offline-first apps, and microservice architectures. Unlike auto-increment IDs, they do not leak record counts or creation order, improving security. This tool uses the browser's native crypto.randomUUID() API, guaranteeing cryptographic-grade randomness.

          


          

            
什么是 UUID v4？

            
UUID（通用唯一识别码）是 RFC 4122 定义的 128 位标识符标准。v4 版本完全基于随机数生成，无需中央注册机构。格式为 8-4-4-4-12 十六进制字符，例如 550e8400-e29b-41d4-a716-446655440000。具有 122 位有效随机位，即便大规模生成也几乎不会碰撞（概率约为 5.3×10³⁶ 分之一）。


            
UUID 作为数据库主键的优势

            
UUID 可在客户端生成，无需数据库往返，非常适合分布式系统、离线应用和微服务架构。与自增 ID 相比，UUID 不会泄露记录数量或创建顺序，安全性更高。本工具使用浏览器原生 crypto.randomUUID() API，保证密码学级别的随机性。