One of the first things I’d look at is image optimization. Large images can significantly increase page load time, especially on mobile devices. Using appropriately sized images, modern formats where possible, and avoiding unnecessary high-resolution assets can make a noticeable difference.
I’d also check which scripts, animations, and third-party apps are actually needed. Reducing unnecessary elements can improve loading and interaction times without changing the overall design.
The important part is to measure the site before and after the changes rather than assuming an optimization helped. That makes it much easier to identify which changes are actually improving performance.
Good points above. If I had to pick one thing on Wix specifically, it would be the first section on mobile.
On a slow Wix site, the hero is very often where most of the time goes: a background video, a big slider or several large images, plus entrance animations on the first strip. On a phone all of that has to load before anything useful shows. Swapping a video background for a single well-sized image on the mobile breakpoint, and removing the animations from that first section, often makes a bigger difference than anything else, and the design stays the same.
Before and after, check the Site Speed page in your dashboard (under Site & Mobile App). It shows how real visitors experienced the site, split into mobile and desktop, so you can see whether the change actually helped.
Two smaller ones that are easy to miss: every extra font and font weight is one more file to download, so sticking to two fonts helps a little. And elements you hide on mobile can still be part of the page, so a heavy element hidden on mobile isn’t always free.