"author": {
      "@type": "Organization",
      "name": "Online UUID Generator"
    },
    "publisher": {
      "@type": "Organization",
      "name": "Online UUID Generator"
    },
    "mainEntityOfPage": {
      "@type": "WebPage",
      "@id": "https://online-uuid-generator.com/versions/v6/"
    }
  }

---

Online UUID Generator - Version 6

UUID Version 6 is a variant of Version 1 that reorders timestamp bits to improve lexicographical sorting. It maintains uniqueness based on the timestamp, clock sequence, and device's MAC address, while also providing improved indexability.

Pros:

• Sortability: Timestamp bits are arranged to allow UUIDs to be sorted chronologically, making it useful for ordered databases.
• Globally Unique: Similar to Version 1, it ensures uniqueness across different devices and over time.

Cons:

• Privacy Concerns: Like Version 1, it includes the device's MAC address, which may raise privacy issues.
• Not Fully Random: Based on time and MAC address, which makes it predictable compared to fully random UUIDs.

Best for: Applications needing chronological sorting and unique identifiers in large-scale, distributed databases, especially where index performance is essential, but privacy is not a major concern.

When to Choose UUID v6

Perfect for:

• Database primary keys requiring chronological sorting
• Large-scale distributed systems
• Applications where index performance is critical
• Time-ordered unique identifiers

Consider alternatives if you need:

• Privacy protection: Use UUID Version 7 without MAC address
• Random IDs: Use UUID Version 4 for unpredictable identifiers
• Deterministic IDs: Use UUID Version 5 for namespace-based generation

Related UUID Versions

Compare with other versions:

• UUID Version 1 - Time-based, less sortable than v6
• UUID Version 3 - MD5 namespace-based
• UUID Version 4 - Random, most popular choice
• UUID Version 5 - SHA-1 namespace-based
• UUID Version 7 - Modern time-based, more private than v6

Database-optimized implementation guides:

• Java - Spring Data JPA and Hibernate optimization
• C# - Entity Framework and SQL Server
• Go - High-performance database applications
• Python - Django ORM and SQLAlchemy
• **View all languages →

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