We are about to move into more complicated topics, but the most important lessons you just learned:
- INP measures all Interactions
- Each Interaction is measured from Input to Next Paint—the way the user sees responsiveness.
- Input Delay, (Event) Processing Times, and then Presentation Delay's, all affect Interaction responsiveness.
- You can measure INP, and Interaction breakdowns, easily!
Lessons:
- Don't have long running code (long tasks) on your pages
- Move needless code out of event handlers until after next paint
- Make sure the Rendering update itself is efficient for browser