Measure different parts of the experience

Google’s Core Web Vitals distinguish loading, responsiveness, and visual stability through LCP, INP, and CLS. Treat those as different questions rather than interchangeable scores. Ask which page element arrives late, which interaction feels delayed, or which content moves unexpectedly. Separate measurements from real visits from controlled test results, because they describe different conditions and can be useful for different reasons.

Choose representative pages and conditions

Include the homepage, a practice page, a biography, and an enquiry route in the review. Test a realistic mobile view as well as a large desktop. Record the device and connection assumptions so comparisons remain meaningful. If a problem appears only after a menu opens or a third-party tool loads, a test of the initial blank state may not reveal the issue.

Give images an appropriate job and size

Use image dimensions and compression suited to the intended display rather than uploading an unnecessarily large original. MDN documents how explicit width and height help the browser reserve space and reduce layout shifts. Consider deferred loading for images farther down the page, while treating immediately visible imagery appropriately. Review the result visually so the file reduction does not make an important portrait or diagram unclear.

Question additions that slow essential tasks

Inventory chat widgets, video players, trackers, and other third-party features. For each, identify its owner and the purpose it serves. Ask whether it needs to load immediately or whether a simpler presentation can satisfy the same need. Check navigation and form behaviour after a change. Performance improvements are most useful when they preserve the information and actions visitors came to use.

Keep a before-and-after record

Make a targeted change, repeat the relevant measurement, and note what improved or regressed. Do not chase a perfect lab score by hiding useful content or breaking interactions. Include performance in the review of new templates and features. A short record of decisions makes it easier to understand why an expensive component was removed and to avoid reintroducing the same problem in the next redesign.

From reading to doing

Put it into practice

  • Separate loading, responsiveness, and stability.
  • Test representative pages and mobile conditions.
  • Right-size images and reserve their space.
  • Compare results after a targeted change.

Reference points: Google web.dev, “Web Vitals”; MDN Web Docs, HTML image element reference. No performance or ranking result is guaranteed. Reviewed September 30, 2026.

General editorial guidance. Assess technical and professional requirements for the actual website, audience, and jurisdiction.