Why speed matters
Real users experience slower pages when assets are large, scripts block rendering or the main content shifts while loading. Run this page through PageSpeed Insights and record the baseline before changing anything.
What to investigate
- Largest Contentful Paint (LCP): loading of the largest visible content element.
- Interaction to Next Paint (INP): responsiveness to user interactions.
- Cumulative Layout Shift (CLS): unexpected visual movement.
Test an image change
Upload a large image through the editor and run a baseline test; then optimise it and re-test. Avoid intentionally adding expensive third-party scripts to a shared site. Performance scores fluctuate, so use multiple runs and compare the diagnostics, not just the overall score.
Open PageSpeed Insights and enter this page URL once published.
Class exercise: Compare mobile and desktop lab measurements and explain the difference between lab data and field data. A new training domain may have no Chrome UX Report field data.
Related exercises: Reference · Metadata · Headings · Content · Images · Speed