← Lessons

quiz vs the machine

Gold1460

System Design

Geo Routing and Latency Based Routing

Two ways to pick a region: by where users are, or by measured speed.

5 min read · core · beat Gold to climb

Two Routing Policies

Once you have several regions, you must decide which one each user reaches. Geo routing and latency based routing answer that differently.

Geo Routing

Routes by the user geographic location.

  • Maps a region or country to a specific site
  • Useful for data residency and legal compliance
  • Predictable, since location maps to a fixed answer
  • May not be the fastest path if the nearest region is overloaded or peered poorly

Latency Based Routing

Routes by measured network latency to each region.

  • Picks the region that historically responds fastest for that user network
  • Adapts to real routing conditions, not just distance
  • Best for raw performance
  • Less predictable and ignores legal location rules

Combining Them

Many systems apply geo rules first for compliance, then latency within the allowed regions for speed.

Key idea

Geo routing maps users to regions by location for predictability and compliance while latency based routing picks the fastest measured region for performance, and systems often layer geo rules over latency choices.

Check yourself

Answer to earn rating on the learn ladder.

1. When is geo routing especially useful?

2. What does latency based routing optimize for?