If your Webflow site feels fast on desktop but slow on iPhone, it’s usually one of three things: heavy hero media, font/script bloat, or layout shifts. This page gives you a do-this-first checklist + quick explanations that help you fix it.
If you only do one thing: fix the hero media + font count + script bloat.
The biggest element at the top (hero image/video/background) is usually your LCP. If that asset is large or poorly sized, mobile will suffer even if desktop looks “fine.”
Too many fonts/weights + third-party scripts delay first render and block interactivity. Mobile devices feel this more because CPU/memory is tighter.
If your page jumps while loading, users lose trust. CLS is often caused by missing dimensions, late-loading content, or sticky UI that pushes layout.
iPhone/Safari can struggle with large blurred layers, constant transforms, and excessive shadows. Use motion selectively and keep effects lightweight on mobile.
“Fast on desktop” doesn’t mean “fast.” Desktop hides performance problems. Mobile exposes them. Fix the largest assets and heaviest scripts first.
The biggest visible element above the fold (often your hero image/text block) takes too long to load.
Your page jumps around while loading. This happens when media lacks size or UI pushes content.
The site feels laggy when you tap/click. Heavy scripts and too much animation can cause delays.
Huge blurred glows look premium, but they can be expensive on mobile. Use smaller glows, gradients, and fewer animated layers—especially above the fold.
Sticky bars should overlay content, not push it down. Pushing causes CLS and feels “glitchy.”
Respect prefers-reduced-motion so users who hate motion get a smooth experience.
Don’t only test in Webflow Designer preview. Test on a real iPhone (Safari + Chrome). Mobile performance issues are often device-specific.
If you want this done fast (and tested on iPhone + desktop), apply for a slot. We’ll reply with the next step if you’re a fit.