Performance: where to begin
Read the guides below in the order that fits your question. Each article includes a relevant primary reference, an original worked approach, and links to the next useful concept. Keep sample illustrations separate from actual site observations as you apply the ideas.
Choose the scenario
Define a representative page family and a repeatable interaction.
Keep contexts separate
Record test conditions alongside the field population and reporting window.
Verify the release
Check the served change, then review an appropriate period of new evidence.
Core Web Vitals: turn LCP, INP, and CLS into a practical action plan
Understand the three experience metrics, keep field evidence separate from diagnosis, and prioritize performance work around real tasks.
Lab testing vs. real-user monitoring: why both belong in your performance workflow
Use controlled tests to investigate causes and field evidence to understand measured experience, without treating their numbers as interchangeable.