Loading the arcade
Performance shapes whether a visitor can see, control and trust a page. Core Web Vitals describe three parts of that experience. They are useful assessment signals—not a promise that a perfect score guarantees rankings.
Largest Contentful Paint
Main screen visible: how soon the largest visible content element finishes rendering.
Good assessment guidance: ≤ 2.5 seconds
Interaction to Next Paint
Controls respond: how quickly the page gives visual feedback after user input.
Good assessment guidance: ≤ 200 milliseconds
Cumulative Layout Shift
Controls stay put: how much visible content moves unexpectedly.
Good assessment guidance: ≤ 0.1
These “good” thresholds are current assessment guidance evaluated at the 75th percentile, not universal ranking guarantees. See web.dev’s Core Web Vitals documentation.
Stable versus unstable playfield
Dimensions reserve the artwork area, so the control stays where the player expects.
A late resource pushes the control after the visitor tries to act.
What slows or shifts a page?
Oversized images
Send appropriately sized, compressed images and prioritise the likely main visual.
Blocking scripts
Remove unused work, defer non-critical code and break up long main-thread tasks.
Missing dimensions
Set image width and height or an aspect ratio so browsers reserve space.
Slow resources
Improve server response, caching and delivery; load fonts and third parties deliberately.
Lab test or real players?
Laboratory data
A controlled simulation useful for debugging and repeatable comparisons. It may not represent every visitor.
Run PageSpeed InsightsReal-user (field) data
Aggregated experiences from eligible real visits, across devices and networks. It reveals what users encountered over time.
Explore Search ConsoleRelated dictionary terms
Level checkpoint / Mission review
Check what you learned
Answer all three questions correctly, then complete the lesson. Retry any answer whenever you need.
Complete all three questions to unlock lesson completion.
Checkpoint cleared
Lesson complete
You can revisit the check above at any time.
Next lesson: Technical Signals and Site Health →