How to make a website faster

01What "fast" means: Core Web Vitals

Google measures page experience with three Core Web Vitals, described on web.dev: Largest Contentful Paint (main content loads within 2.5 seconds), Interaction to Next Paint (responds to input within 200 milliseconds) and Cumulative Layout Shift (layout stays stable, 0.1 or less), each measured at the 75th percentile of real visits. They are a good target because they track what visitors actually feel.

02Fix 1: Images

Images dominate page weight on most sites; the HTTP Archive's 2025 Web Almanac reports the median mobile home page loads about 911 KB of images. Most of that can be saved without visible loss.

1. 1Resize to display sizeDo not ship a 4000-pixel photo into a 800-pixel slot.
2. 2Use modern formatsWebP or AVIF are much smaller than JPEG or PNG for the same quality.
3. 3Lazy-load below the fold onlyGoogle's LCP guide says never to lazy-load the LCP image.
4. 4Prioritize the heroMark the main image with fetchpriority="high" so it loads first.
5. 5Set width and heightReserved space prevents layout jumps (CLS).

03Fix 2: JavaScript and third-party scripts

JavaScript blocks rendering and slows interaction. Remove scripts you no longer use, defer what is not needed for the first view, and audit third-party tags: chat widgets, analytics, heatmaps and ad scripts each add requests and processing. Load them after the page is usable, or not at all. Google's LCP optimization guide also recommends avoiding synchronous scripts in the page head.

04Fix 3: Fonts, CSS and hosting

• Load only the font weights you use, and prefer variable fonts; best fonts for websites covers this.
• Let text show immediately in a fallback font while web fonts load.
• Inline the small CSS needed for the first screen; load the rest normally.
• Serve from a CDN so pages come from a location near each visitor.
• Cache static files for a long time; change file names when they change.
• Reduce server response time; a slow first byte delays everything else.

05Fix 4: Layout shifts and responsiveness

Speed is not only loading. Pages that jump as images, ads or banners appear frustrate visitors and fail the layout-shift metric; reserve space for every image and embed, and avoid inserting banners above content after the page loads. Pages that react slowly to taps usually run too much JavaScript at once; breaking up long tasks and removing unneeded scripts improves Interaction to Next Paint. Both problems are easiest to spot by using your own site on a mid-range phone for a few minutes.

06How to measure and prioritize

Run PageSpeed Insights on your most important pages. It shows real-user data when available and lab diagnostics ranked by impact. Fix the top item, measure again and repeat; a few fixes usually deliver most of the gain. Check on a mid-range phone as well as a laptop.

Speed affects both visitors and search; does page speed affect SEO? explains how much. If your site is built on a heavy theme or builder, sometimes the biggest win is a lighter foundation; static vs dynamic website explains why pre-built pages are fastest.