Improve mobile page performance
Cut image weight, JavaScript, and server lag so the page loads fast on phones.
What it means
Your mobile Lighthouse score blends how fast the page loads, how quickly it becomes interactive, and how stable it is while loading. Phones have slower CPUs and networks than desktops, so the same page scores much lower there.
Why it matters
Over 60% of web traffic is mobile, and Google ranks your site primarily by its mobile version. A low mobile score means most of your visitors are getting your worst experience.
How to fix it
- Compress and resize every image to the size it's actually displayed at, and serve WebP/AVIF (see our image format guide).
- Enable compression (gzip/brotli) and browser caching on your server or CDN.
- Remove unused CSS and JavaScript — most page builders ship far more code than a page uses.
- Reduce third-party scripts to the minimum that earns its keep.
- Check your hosting: if server response (TTFB) is over ~0.8s, a CDN or better hosting will lift every other metric too.
Helpful tools
- PageSpeed Insights
- WebPageTest
- Chrome DevTools → Lighthouse
Not sure if this affects your site? Analyze your website for free or compare it with a competitor.
Related guides
- Fix slow Largest Contentful Paint (LCP): Make the biggest visible element on your page load in under 2.5 seconds.
- Stop layout shifting (CLS): Reserve space for images and embeds so the page stops jumping while loading.
- Reduce Total Blocking Time (TBT): Break up long JavaScript tasks so the page stays responsive to taps and clicks.
- Convert images to WebP or AVIF: Modern image formats are 25–50% smaller than JPEG/PNG at the same visual quality.