Page Speed
How quickly a web page loads and becomes interactive for users.
The Definition
Page speed encompasses multiple metrics including Time to First Byte (TTFB), First Contentful Paint (FCP), Largest Contentful Paint (LCP), and Time to Interactive (TTI). It is influenced by server response time, resource optimization, caching strategies, code efficiency, and content delivery network (CDN) usage.
Why It Matters
Page speed is a direct Google ranking factor and a core component of user experience. 53% of mobile users abandon sites that take longer than 3 seconds to load. Faster pages also get crawled more frequently by search engines, improving indexation speed.
Best Practices
Use a CDN to serve static assets from locations geographically close to your users
Enable Brotli or Gzip compression for all text-based resources (HTML, CSS, JS, SVG)
Implement effective browser caching with appropriate Cache-Control headers for static assets
Preload critical resources (fonts, above-the-fold images, key CSS) with <link rel="preload">
Minimize main thread work by reducing JavaScript execution time and splitting long tasks
Use resource hints (preconnect, dns-prefetch) for critical third-party origins
Mistakes to Avoid
- 1
Loading all JavaScript synchronously in the head instead of deferring non-critical scripts
- 2
Serving uncompressed resources, increasing transfer sizes by 60-80% unnecessarily
- 3
Not leveraging browser caching, forcing repeated downloads of unchanged static assets
- 4
Running too many synchronous third-party scripts that block the main thread and delay interactivity
Audit Checks
How Digispot AI identifies and fixes related issues
The page is slow to visually fill in (poor Speed Index).
Impact: A slow visual fill makes the page feel sluggish even if it technically loads, lowering satisfaction.
Prioritize above-the-fold content. • Remove render-blocking CSS and JavaScript. • Inline critical styles.
The page is slow to respond when a visitor interacts with it — taps, clicks and key presses lag (Interaction to Next Paint, or INP, over 200ms).
Impact: INP is a Core Web Vital and Google ranking signal; a laggy interaction makes the page feel broken and drives visitors away.
Break up long JavaScript tasks so the main thread can respond sooner. • Defer or remove scripts that aren't needed for the first interaction. • Move heavy computation off the main thread (web workers).
Content jumps around as the page loads — buttons or text shift under the reader (a high Cumulative Layout Shift, or CLS, over 0.1).
Impact: Layout jumps frustrate visitors with mis-clicks and lower your Google ranking.
Set explicit width and height on every image and video. • Reserve space for ads, embeds, and banners before they load. • Avoid inserting content above what the reader is already viewing.
The HTML document alone is larger than 2MB — past Google's documented 2MB indexing limit. Images, CSS and JS are fetched separately and do NOT count toward this.
Impact: Google only indexes the first 2MB of HTML, so any content past that point in the document risks never being indexed.
Trim large inline scripts and JSON embedded in the HTML. • Paginate huge lists and move bulk data out of the initial HTML. • Enable server-side compression to shrink the document below 2MB.
The biggest thing on the page — usually the hero image or main heading — takes more than 2.5 seconds to appear (its Largest Contentful Paint, or LCP).
Impact: Google uses LCP as a ranking signal, and visitors often leave before a slow page finishes loading.
Compress the largest above-the-fold image and serve it as WebP or AVIF. • Preload that hero image and your main web font so they load first. • Remove or defer render-blocking scripts and CSS.
Some CSS or JavaScript must finish loading before the page can show anything.
Impact: Render-blocking resources delay the first paint, making the page feel slow.
Defer or async-load non-critical JavaScript. • Inline the critical CSS the first view needs. • Move the rest of the CSS to load later.