Speed guide · November 2026

Why Salesforce Commerce Cloud stores are slow on phones

Short answer: on the 6 Salesforce Commerce Cloud stores we measured, the main cause was not the platform's servers. It was what the phone has to do after the page arrives: too much JavaScript to run (on 5 of 6), other companies' scripts, and images far heavier than a phone needs (4 of 6 home pages weighed 10 MB or more). 0 of 6 showed their main content within Google's 2.5 s mark for good; 4 took over 9 seconds.

What we measured

The home page of 6 US stores running Salesforce Commerce Cloud (the classic storefront or the newer PWA Kit storefront), loaded once each with Google's Lighthouse on a simulated mid-range phone with slow 4G, in November 2026.

Lab numbers: real visitors on fast phones and Wi-Fi see faster pages. The causes are the same. For comparison, the middle store of the 88 big US store sites we ranked took 9.2 s.

The four causes we keep finding

1. Too much JavaScript for a phone's processor. The phone has to download, read and run every script before the page answers taps. On the slowest stores the processor stayed busy for 20 to 30 seconds. The usual sources are the storefront's own bundles, plus tag managers that add a new script for every campaign and never remove old ones.
   Check first: in Chrome's Performance panel, which scripts take the most time, and who still needs them.
2. Other companies' scripts. Chat, reviews, personalization, ads and tracking each add their own work. On some stores we measured they kept the phone busy longer than the store's own code.
   Check first: Lighthouse's "third-party" list. Load the ones nobody needs on the first screen after the page shows.
3. Images bigger than a phone screen. Several home pages sent desktop-size banners and product pictures to phones, and loaded pictures far below the fold before anyone scrolled. Commerce Cloud's image service can resize and compress pictures on request (width and quality settings in the image address); many stores don't use it on the home page.
   Check first: the size of the main banner on a phone, and whether pictures below the fold load late.
4. Files that block the first paint. Style sheets and scripts in the page head that the browser must finish before it draws anything. On some stores this alone cost about 2 seconds.
   Check first: Lighthouse's "render-blocking" list.

Why it matters

In Deloitte's 2020 study Milliseconds Make Millions (37 brands, 30 million sessions), a site just 0.1 s faster on phones went with 8.4% more orders for retail sites. Google also uses real visitors' speed as a search ranking signal.

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