Performance reports produce a single number out of a hundred, and that number becomes the goal. It is a poor proxy. A site can score in the nineties on a developer’s laptop and feel broken on a mid-range phone on mobile data.
Measure on the device people use
Test on a mid-range Android handset over a throttled mobile connection. That is the honest baseline for most of the traffic reaching a Bangladeshi business. Desktop-on-fibre numbers describe an audience you mostly do not have.
The three that count
- Largest Contentful Paint — when the main thing on the page is visible. Under about 2.5 seconds on mobile
- Interaction to Next Paint — how long the page takes to respond when tapped. Under about 200 milliseconds
- Cumulative Layout Shift — how much the page moves while loading. Near zero
The third causes the most damage per unit of engineering effort. A layout that shifts as images and ads load makes people tap the wrong thing, and they blame the business rather than the site.
Where the time usually goes
- Uncompressed images — still the single biggest win on most sites we audit
- Third-party scripts: chat widgets, tag managers, ad pixels, each loading more of its own
- Webfonts loading without a fallback, leaving text invisible while they arrive
- Images and embeds with no dimensions, which is what causes the layout to jump
What to do first
Compress and correctly size your images. Set explicit width and height on everything. Then audit your third-party scripts and remove the ones nobody can name an owner for — there are usually two or three.
That list is unglamorous and it will get you most of the available improvement. The remaining points cost far more per point and almost never change what a customer does.
- Performance
- SEO