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UUID Versions Explained: v1, v3, v4, v5
•7 min read
Overview of UUID Versions
There are five UUID versions, each designed for different use cases. The most commonly used are v1, v4, and v5.
UUID v1: Time-Based
Generated from timestamp and MAC address. Pros: sortable and time-ordered. Cons: can expose hardware information.
Use when: You need time-ordered identifiers and don't mind exposing MAC addresses.
UUID v4: Random
Generated using random or pseudo-random numbers. This is the most popular version.
Use when: You need unpredictable, secure identifiers without any information leakage.
UUID v3 & v5: Name-Based
Generated by hashing namespace and name (v3 uses MD5, v5 uses SHA-1). Deterministic - same input produces same UUID.
Use when: You need reproducible UUIDs from known inputs.
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