Performance & Speed Optimization

Every 1 second delay results in conversion drop on your store!

“Your website should be built to load fast, and seamlessly — pages should load instantly, interactions should happen immediately, and content should appear without any frustrating delays — so that your potential customers can browse, shop, or explore without waiting endlessly, on any device. This is where performance & speed optimization comes in”

Performance & speed optimization checklist for mobile and desktop apps:

FCP Actions:

  • Render above-the-fold content first.
  • Compress images (WebP/AVIF) and serve scaled sizes.
  • Inline critical CSS for main layout.
  • Preload important fonts (<link rel="preload">).
  • Minimize render-blocking JS (defer or async).

LCP Actions:

  • Prioritize loading of hero banners, key images, and headings.
  • Lazy-load below-the-fold images and videos.
  • Use server-side rendering (SSR) if possible.
  • Use CDN or edge servers for large assets.

TTI Actions:

  • Break heavy JS into smaller chunks.
  • Defer non-critical scripts.
  • Offload expensive calculations to Web Workers (web) or background threads (apps).
  • Optimize animation loops and event listeners.

CLS Actions:

  • Set explicit width/height for images and videos.
  • Avoid inserting dynamic content above existing elements.
  • Use CSS aspect-ratio or min-height boxes.
  • Reserve space for ads and third-party widgets.

TBT Actions:

  • Optimize JS execution — split, lazy load, or remove unused code.
  • Debounce or throttle scroll, resize, and input events.
  • Remove synchronous XHR requests; use async fetch instead.
  • Use GPU acceleration for animations.

Mobile Specific Optimization:

  • Compress images aggressively.
  • Avoid heavy frameworks for simple screens.
  • Reduce main-thread CPU spikes.
  • Optimize touch gestures.

Desktop Specific Optimization:

  • Lazy-load offscreen images and widgets.
  • Optimize analytics & third-party scripts.
  • Use HTTP/2 or QUIC for faster delivery.
  • Cache assets for repeat visitors.

If all of this sounds like a jargon then feel free to give a quick shout out.