Practical steps in order.
MEASURE FIRST
Test with a performance tool, on mobile. Look at what is actually taking time.
THE ORDER TO WORK
- Compress and resize images. Usually the largest gain by far.
- Enable caching.
- Remove plugins you do not use.
- Update PHP to a current version.
- Remove unnecessary third-party scripts: chat widgets, trackers, embedded video.
- Reduce the number of fonts and weights.
- Add a CDN.
IMAGES
A single unoptimised photograph can be larger than an entire well-built page. This is where most sites lose their speed.
THIRD-PARTY SCRIPTS
Frequently the slowest part of a page, and you control none of their code. Audit what is loading and remove what does not earn its place.
WHAT NOT TO DO
Buy a bigger hosting plan before optimising. A slow site is slow on any plan.
MEASURING PROGRESS
Test after each change. That tells you what helped, which is more useful than doing everything at once.
THE TARGET
A page appearing within a couple of seconds on a mobile connection.