UUID v4 vs v1: Which Should You Use?
Choosing between UUID v4 and v1 depends on your specific requirements. Let's break down the differences and help you make the right choice for your application.
UUID v4: Random
UUID v4 is the most commonly used version. It's generated using random or pseudo-random numbers, making each UUID essentially unpredictable.
- Pro: Completely random, no information leakage
- Pro: Simple to generate
- Pro: Widely supported in all programming languages
- Con: Not sortable by creation time
- Con: Can cause database index fragmentation
UUID v1: Timestamp
UUID v1 incorporates the current timestamp and the machine's MAC address, making it time-ordered and traceable.
- Pro: Naturally time-ordered
- Pro: Better database index performance
- Pro: Guaranteed unique even at high generation rates
- Con: Exposes timestamp information
- Con: Can expose MAC address (privacy concern)
When to Use Each
Use UUID v4 When:
- Privacy is important
- You need unpredictable IDs
- Time ordering doesn't matter
- Simple generation is preferred
Use UUID v1 When:
- You need time-sorted IDs
- Database performance is critical
- Tracking creation time matters
- Privacy isn't a concern
Generate Both Versions
Try our UUID generator to create v1 or v4 UUIDs instantly with custom formatting options.
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