Mobile Page Speed
Loading speed on mobile devices. More critical than on desktop due to slower networks.
On this page
Why mobile speed mattersTarget metricsMobile optimisation tipsTesting toolsSimulating a slow networkMobile vs desktopIn brief
Mobile page speed is the time required to fully load and render a page on a smartphone or tablet. Due to limitations of mobile networks (3G/4G) and less powerful CPUs, speed metrics on mobile are typically worse than on desktop and require dedicated optimisation.
Why mobile speed matters
- Slower networks — 3G/4G is slower than Wi‑Fi
- Weaker CPUs — slower JS parsing
- Bounce rate — 53% of users leave if load > 3 seconds
- Conversion — each extra second lowers conversion by 7%
Target metrics
- LCP < 2.5 sec (mobile and desktop)
- FID/INP < 200 ms
- CLS < 0.1
- FCP < 1.8 sec
Mobile optimisation tips
- Images — WebP, compression, responsive images
- JavaScript — minification, code splitting, defer/async
- CSS — inline critical CSS, minification
- Fonts — font-display: swap
- Caching — aggressive caching
- CDN — serve from nearest servers
- AMP — for news and blogs (optional)
Testing tools
- PageSpeed Insights — Mobile tab
- Chrome DevTools — network throttling
- WebPageTest — test on real mobile devices
- Lighthouse — mobile audit
Simulating a slow network (Chrome DevTools)
TXT
1. F12 → Network tab
2. Throttling → Slow 3G
3. Reload the page
4. Analyse: what blocks loadingMobile vs desktop
- Mobile is typically 30-50% slower than desktop
- JS parsing takes longer due to weaker CPUs
- Images impact bandwidth more
Mobile speed directly affects Google rankings, especially after Mobile‑First Indexing and Core Web Vitals.
FAQ
Common questions
Optimise the Largest Contentful Paint element (usually an image or video). Compress media, use responsive images (srcset), and set up preloading of critical resources.
Interaction to Next Paint measures responsiveness. Improve by reducing long JS tasks, code splitting, and avoiding heavy event handlers.
AMP is no longer required for Top Stories, but may still benefit very slow sites. Modern optimisation typically achieves good scores without AMP.
Direct contacts
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