Why your store is slow on mobile, and what it costs

Almost every store is fast in the office and slow in the wild. The office has a fast laptop, a good connection and a warm cache. Your customer has a three-year-old phone on mobile data, and that is where the revenue is.

The cost, concretely

Abandonment climbs sharply with load time, and the effect compounds through a funnel. A slow product page loses browsers; a slow cart loses people who had already decided. The second group is far more expensive to lose because you paid to acquire them and they were ready to pay you.

Ranked causes on a typical store

1. 01Apps and third-party scripts. Reviews, chat, popups, analytics, loyalty, upsell widgets. Each was added for a reason and none was removed. Count them in the network tab; twelve is common and half are usually unused.
2. 02Unoptimised images. Product photos exported at print resolution, served at 400px. Modern formats typically cut 60 to 80 percent with no visible change.
3. 03Theme bloat. Multi-purpose themes ship code for every feature including the ones you disabled.
4. 04Fonts. Several weights, loaded from a third-party domain, blocking text from rendering.
5. 05Popups and banners that inject after paint, shoving the page down as someone is reaching for a link.

Find yours in ten minutes

1. 01Open your store on an actual mid-range phone on mobile data. Not the simulator. Watch what happens.
2. 02Run PageSpeed Insights and read the field data section rather than the lab score. Field data is real visitors.
3. 03In your platform admin, list installed apps and mark the ones nobody has opened in three months.
4. 04Open the network tab, sort by size, and look at the top ten requests.

In our experience three or four items explain most of the problem, and the rest is noise. Fixing the top three is usually a day of work and worth more than a redesign.

The one to check first

Uninstall the apps you are not using. It is free, takes an afternoon, requires no developer, and on most stores it is the single biggest available improvement. It also reduces your monthly bill, which is a rare combination.