INP is now the primary responsiveness metric in Core Web Vitals, capturing interactions across the page lifecycle. Reduce long tasks and main‑thread blocking to keep Interaction to Next Paint consistently fast.
Which threshold is commonly referenced as a ‘good’ INP benchmark in 2025?
100 ms or less
1,000 ms or less
500 ms or less
200 ms or less
INP differs from FID primarily because it ______.
only measures cumulative layout shift
measures the latency of the entire interaction, not just the initial input delay
is a server uptime metric
ignores JavaScript execution time
A practical way to lower INP on JavaScript‑heavy pages is to ______.
force all logic into a single synchronous task
increase bundle size to avoid network overhead
split long tasks and defer non‑critical work to idle periods
disable caching entirely
Which interaction types are counted by INP?
Mouse hover only
Clicks, taps, and keyboard interactions
Scroll inertia only
Pointerenter/leave only
Why do field data and RUM matter for INP assessment?
They reflect real‑user devices, networks, and behavior rather than ideal lab setups
They exclude all mobile traffic
They measure server CPU usage only
They ignore network latency
Main sources of poor INP typically include ______.
CDN POP geography alone
long tasks, excessive JavaScript on the main thread, and heavy event handlers
image alt text length
unused CSS classes
Which technique can improve responsiveness without changing features?
force synchronous XHR calls
yield periodically with scheduling (e.g., requestIdleCallback or postTask)
disable HTTP/2
inline every image as data URIs
How does preloading critical assets influence INP?
It blocks user input events by default
It shortens time to interactive response by ensuring needed resources are ready when inputs occur
It disables caching for preloaded assets
It increases layout shift by design
Why might heavy third‑party scripts hurt INP?
They compete for main‑thread time and can add expensive event handlers
They cannot block the main thread
They reduce CLS automatically
They run only on service workers
What’s a sensible KPI pair when optimizing for INP at scale?
Number of redirects on unrelated domains
Total trackers blocked by ad‑blockers
Share of visits with INP ≤ 200 ms and count of long tasks per page
Average hero image size and number of fonts
Starter
Starter: Focus on reducing long tasks and heavy handlers; target INP ≤ 200 ms on key pages.
Solid
Solid: Refactor hotspots and preload critical assets; monitor long‑task counts and INP distribution.
Expert!
Expert: Systematic scheduling, third‑party governance, and field‑based guardrails keep INP tight.
