The added weight.
WHY THEY ARE SLOWER
Multilingual plugins add queries to every request More content in the database Language detection logic Frequently more plugins overall
WHAT TO DO
Caching, configured to cache each language version separately Database optimisation Removing anything unnecessary
THE CACHING POINT
Caching must be language-aware.
Without it, a visitor may receive a cached page in the wrong language.
Check your caching plugin supports your multilingual plugin.
WHAT TO TEST
Each language, cached, in a private window.
Confirm you get the right language.
WHAT BREAKS
Language-based and location-based content conflicting with caching.
That is the most common multilingual performance problem.
FOR SHOPS
Multilingual plus shop plus caching is genuinely complex.
Test thoroughly, in every language.
WHAT TO MONITOR
Resource usage, which rises with a multilingual plugin.
