Working, and too slowly.
MEASURE FIRST
Load a plain static file. If that is fast while pages are slow, the problem is your application rather than the server.
Run the site through a performance tool and look at the waterfall.
SLOW FIRST RESPONSE
No caching A slow database query, usually missing an index A heavy plugin An external API call during page load An outdated PHP version Resource limits being approached
SLOW ASSETS
Large unoptimised images Too many separate files Third-party scripts
THE ORDER OF FIXES
Enable caching Compress and resize images Remove unused plugins Update PHP Add a CDN
FINDING SLOW QUERIES
Enable the slow query log, or use a profiling tool. A single unindexed query on a grown table is the most common cause of a site that was fast and is now slow.
EXTERNAL SERVICES
If your code calls an external API during page load, their slowness becomes yours. Add timeouts and caching.
WHAT TO SEND US
Your performance report and the times affected.
