📚Dev Reference

UUID Versions Guide

Differences between v1, v4, and v7 UUIDs.

Explanation

UUIDs are unique identifiers that can be generated without a central authority.

Examples

v4
Output
Randomly generated
v7
Output
Time-sorted random

Code Examples

Versions 
v1 - Time + Node (MAC address)
v4 - Purely random (Most common)
v5 - Name-based (Deterministic)
v7 - Time-ordered (Best for DBs)

Try it Now

Open in UUID Generator

💡 Tips

  • Use v4 for general purpose random IDs
  • Use v7 if you want your IDs to be sortable by creation time
  • v4 is the default for most libraries

⚠️ Common Pitfalls

  • v1 can leak the server's MAC address
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