Summary

What: Interaction to Next Paint (INP) is Google’s new Core Web Vitals metric that replaced First Input Delay (FID) on March 12, 2024, measuring page responsiveness throughout the entire user journey.

Who: SEO professionals, web developers, digital marketers, and website owners who need to optimize for Google’s current Core Web Vitals standards.

Why: FID had significant limitations, measuring only the first interaction, while INP provides a comprehensive evaluation of overall page interactivity and responsiveness.

When: The official transition happened March 12, 2024, with FID being deprecated and removed from Google Search Console and all Core Web Vitals reporting tools.

How: INP measures all user interactions (clicks, taps, keypresses) throughout page lifecycle, reporting the worst representative interaction as the final score, unlike FID which only tracked initial input delay.

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Introduction

On March 12, 2024, Google made a seismic shift in how it measures website responsiveness. First Input Delay (FID) was officially replaced by Interaction to Next Paint (INP) as a Core Web Vitals metric. This wasn’t a minor tweak—it fundamentally changed how Google evaluates user experience.

While 93% of websites passed FID on mobile devices, only 65% met the good INP threshold. This dramatic gap reveals that many sites appearing “responsive” under old standards are actually delivering poor user experiences.

For SEOs and developers, understanding INP vs FID isn’t optional—it’s critical for maintaining search visibility, user engagement, and conversion rates. Early data shows INP scores are 35.5% worse than FID on mobile and 14.1% worse on desktop, meaning sites that previously passed responsiveness checks now face serious optimization challenges.

This comprehensive guide explains everything you need to know about INP vs FID, including the critical differences, why Google made the change, how to measure both metrics, proven optimization strategies, and what this means for your SEO and development workflows.

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What is First Input Delay (FID)?

First Input Delay (FID) was Google’s original Core Web Vitals metric for measuring page responsiveness, introduced in 2020 as part of the Core Web Vitals initiative.

How FID Worked

FID measured the time from when a user first interacted with your page (clicking a link, tapping a button, entering form data) to when the browser could actually begin processing that interaction.

What FID Captured:

• First interaction only (not subsequent interactions)
• Input delay before event handler execution
• Time blocked by long-running JavaScript tasks
• Browser’s ability to respond to initial user input

FID Components: FID specifically measured the delay between user action and event handler execution start. It did not measure the processing time of the event handler or the time to paint the result.

FID Limitations

Despite being a significant improvement over synthetic metrics like Total Blocking Time (TBT), FID had critical blind spots that limited its effectiveness:

1. First Impression Only: FID measured only the very first interaction on a page. If that interaction was fast but every subsequent interaction was slow, FID still showed a good score.

2. Load-Time Bias: FID primarily captured interactions during page load when users were most likely to make their first input. It missed interactivity issues throughout the page lifecycle.

3. Incomplete Picture: FID didn’t measure event processing time or presentation delay—just the initial input delay. A page could have a good FID but still feel unresponsive due to slow event handlers.

4. High Pass Rates: 93% of sites passed FID on mobile, suggesting the metric wasn’t capturing real responsiveness problems users experienced.

Real-World Example:

User clicks an accordion to expand content:

• FID measurement: Time from click to event handler start (e.g., 50ms) = Good FID
• Actual user experience: Event handler takes 400ms to process, plus 100ms to render = 550ms total delay = Poor experience

FID would report 50ms (good), but the user experienced 550ms of unresponsiveness.

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What is Interaction to Next Paint (INP)?

Interaction to Next Paint (INP) is Google’s current Core Web Vitals metric for responsiveness, officially replacing FID on March 12, 2024.

How INP Works

INP measures the latency of all user interactions throughout the entire page visit, from initial load until the user leaves. It reports a single value representing the worst (or nearly worst) interaction delay.

What INP Captures:

• All qualifying interactions during page lifecycle
• Complete interaction latency (input delay + processing + presentation)
• Visual feedback responsiveness
• Real-world interactivity throughout user journey

Qualifying Interactions: INP only measures specific user actions:

• Mouse clicks
• Taps on touchscreen
• Physical or on-screen keyboard presses

Excluded from INP:

• Scrolling
• Zooming
• Hover events (without click)

INP Components

INP consists of three critical phases that together represent the complete interaction cycle:

1. Input Delay Time from user action to event handler execution start. Caused by main thread being busy with other tasks (long JavaScript execution, rendering work, etc.).

2. Processing Time Duration of event handler callbacks running to completion. Includes all JavaScript code executed in response to the interaction.

3. Presentation Delay Time from event handler completion to next frame paint showing visual feedback. Includes browser rendering work needed to display the interaction result.

INP Calculation:

• Input Delay + Processing Time + Presentation Delay = Total Interaction Latency
• INP = Worst representative interaction (50th+ pages) or worst interaction (under 50 interactions)

How INP Selects Which Interaction to Report

For pages with fewer than 50 interactions: INP reports the single worst interaction latency

For pages with 50+ interactions: INP reports the 98th percentile of interaction latency (the worst interaction after discounting the top 2% of outliers)

Why This Matters: This approach ensures INP captures persistent responsiveness problems rather than one-off anomalies while still reflecting the worst experiences users encounter.

Discover how our performance marketing services help optimize technical metrics for better user experience.

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Key Differences Between INP and FID

Understanding the fundamental differences between INP and FID is essential for effective optimization. Here’s a comprehensive comparison:

Scope of Measurement

FID (Deprecated):

• Measured only the first interaction on the page
• Captured initial user impression
• Limited to page load phase
• Single data point per page visit

INP (Current):

• Measures all qualifying interactions
• Captures complete user journey
• Evaluates entire page lifecycle
• Multiple data points synthesized into representative score

What Gets Measured

FID Measured:

• Input delay only
• Time from user action to event handler start
• Main thread availability at moment of first input

INP Measures:

• Complete interaction cycle
• Input delay + processing time + presentation delay
• Visual feedback responsiveness
• Total time to visible result

Calculation Method

FID Calculation: Simple measurement of single event: Time from user interaction to event handler execution start = FID value

INP Calculation: Complex analysis of all interactions:

1. Measure latency for every qualifying interaction
2. For pages with 50+ interactions, use 98th percentile
3. For pages with fewer interactions, use worst single interaction
4. Report as final INP value

Pass Rates and Difficulty

FID Pass Rates (Before Deprecation):

• 93% of mobile sites passed (good FID)
• 96% of desktop sites passed
• Relatively easy to achieve good scores

INP Pass Rates (Current Data):

• Only 65% of mobile sites pass (good INP)
• Approximately 70% of desktop sites pass
• Significantly more challenging optimization target

Real-World Impact

FID Limitations: A site could have excellent FID but terrible user experience:

• First interaction during load: 50ms (good FID)
• All subsequent interactions: 500-1000ms (poor responsiveness)
• FID reports: Good
• Actual UX: Poor

INP Advantages: INP captures real responsiveness throughout user journey:

• First interaction: 80ms
• Middle interactions: 150ms, 180ms, 220ms
• Worst interaction: 450ms
• INP reports: 450ms (needs improvement)
• Actual UX: Accurately reflected

Comparison Table

Aspect	FID (Deprecated)	INP (Current)
Scope	First interaction only	All interactions
Measurement	Input delay only	Input delay + processing + presentation
Lifecycle	Page load phase	Entire page visit
Calculation	Single value	98th percentile or worst
Good Threshold	≤100ms	≤200ms
Pass Rate (Mobile)	93%	65%
User Experience	Limited insight	Comprehensive view
SEO Impact	Ranking factor (until 3/12/24)	Current ranking factor

Learn how our web design and development services implement performance-first architecture.

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Why Did Google Replace FID with INP?

Google’s decision to replace FID with INP wasn’t arbitrary—it was driven by clear limitations in FID’s ability to measure real-world user experience.

FID’s Critical Blind Spots

1. First Interaction Bias FID measured only the first interaction, creating a massive blind spot for ongoing responsiveness.

Real-World Scenario: E-commerce product page:

• User lands on page, clicks product image (first interaction): 60ms = Good FID
• User opens size selector dropdown: 420ms
• User adds to cart: 380ms
• User opens quick view modal: 510ms

FID reports 60ms (good), but the user experienced three slow interactions that damaged trust and conversion potential.

2. Incomplete Interaction Measurement FID measured input delay but ignored processing time and presentation delay, missing major sources of perceived slowness.

Example: Button click interaction:

• Input delay (FID measures): 40ms
• Event handler processing (FID ignores): 380ms
• Presentation delay (FID ignores): 90ms
• Total user experience: 510ms (poor)
• FID reports: 40ms (good)

3. Load-Phase Limitation Most first interactions occurred during page load when JavaScript was still executing. This meant FID primarily measured load-time responsiveness, not interactive-phase responsiveness.

4. High Pass Rates Disguising Problems 93% pass rate suggested FID wasn’t effectively identifying sites with responsiveness issues that users actually experienced.

What INP Fixes

1. Comprehensive Coverage INP measures all interactions throughout page lifecycle, capturing responsiveness problems FID missed.

2. Complete Latency Measurement By measuring input delay + processing + presentation, INP reflects what users actually experience: the time from action to visible feedback.

3. Lifecycle-Wide Evaluation INP evaluates responsiveness from load through all user activity until page exit, matching real usage patterns.

4. Realistic Standards 65% pass rate indicates INP effectively distinguishes truly responsive sites from those with hidden problems.

Google’s Official Statement

According to Google’s announcement, <cite index=”33-1″>”After another year of testing and gathering feedback from the community, we’re ready to take the training wheels off and announce that INP is no longer experimental. Furthermore, effective March 2024, we’re also committed to promoting INP as the new Core Web Vital metric for responsiveness, replacing FID.”</cite>

The Chrome team emphasized that <cite index=”34-1″>”INP will officially become a Core Web Vital and replace FID on March 12 of this year, and that FID will be deprecated in this transition.”</cite>

Industry Response

The transition revealed significant optimization challenges. One analysis found that <cite index=”41-1″>”on mobile, INP scores are 35.5% worse than FID on average. When reviewing desktop performance across the same dataset, there was only a 14.1% drop on average.”</cite>

This dramatic difference confirms that FID was masking widespread responsiveness problems that INP now exposes.

Check our case study on 746% increase in organic traffic achieved through technical optimization.

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How INP and FID Are Measured

Understanding the technical measurement differences between INP and FID helps developers optimize effectively.

FID Measurement Process

Step 1: User Makes First Input User clicks, taps, or presses key for the first time on the page.

Step 2: Browser Attempts to Respond Browser checks if main thread is available to process event handler.

Step 3: Delay Measurement Time from Step 1 to when event handler can start executing = FID value.

FID Formula:

FID = Time from user input → Event handler execution start

FID Timeline Example:

User Click (t=0ms)
↓
[Main thread busy with JavaScript: 85ms]
↓
Event Handler Starts (t=85ms) → FID = 85ms

INP Measurement Process

Step 1: Capture All Interactions Browser records latency for every qualifying interaction (clicks, taps, keypresses) throughout page visit.

Step 2: Measure Complete Latency For each interaction:

1. Input delay (time to event handler start)
2. Processing time (event handler execution duration)
3. Presentation delay (time to next paint)

Step 3: Select Representative Value

• Pages with <50 interactions: Use worst interaction
• Pages with 50+ interactions: Use 98th percentile

Step 4: Report INP The selected value becomes the page’s INP score.

INP Formula:

INP = Input Delay + Processing Time + Presentation Delay
(for worst or 98th percentile interaction)

INP Timeline Example:

User Click (t=0ms)
↓
[Input Delay: Main thread busy - 45ms]
↓
Event Handler Starts (t=45ms)
↓
[Processing: Handler execution - 180ms]
↓
Event Handler Completes (t=225ms)
↓
[Presentation Delay: Rendering work - 65ms]
↓
Visual Feedback Painted (t=290ms) → INP = 290ms

Key Measurement Differences

What FID Captures:

[Input Delay]
User Action → → → Event Handler Start
         ⬆
      This gap only

What INP Captures:

[Input Delay] + [Processing] + [Presentation]
User Action → → → Handler Start → → → Handler End → → → Visual Paint
         ⬆                                          ⬆
               Entire interaction latency from start to visible result

Real User vs Lab Data

FID Characteristics:

• Field metric only (requires real user interaction)
• Cannot be measured in lab/synthetic testing
• Available through CrUX, RUM providers
• No lab equivalent for exact replication

INP Characteristics:

• Primary field metric (real users)
• Can be measured in lab with simulated interactions
• Available through CrUX, RUM, PageSpeed Insights
• Chrome DevTools supports INP debugging

Lab Alternative for FID: Total Blocking Time (TBT) was used as a lab proxy for FID.

Lab Measurement for INP: Can directly test INP in Chrome DevTools by simulating interactions and measuring response times.

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INP vs FID: Scoring Thresholds and What They Mean

Both metrics use three-tier threshold systems, but with different values reflecting their distinct measurement scopes.

FID Thresholds (Deprecated)

Good: ≤100 milliseconds

• Excellent responsiveness
• Users feel instant feedback
• No perceptible delay
• Optimal user experience

Needs Improvement: 100-300 milliseconds

• Noticeable but acceptable delay
• Most users don’t complain
• Room for optimization
• Should prioritize improvements

Poor: >300 milliseconds

• Significant delay
• Users notice lag
• Negative impact on experience
• Urgent optimization needed

INP Thresholds (Current)

Good: ≤200 milliseconds

• Responsive interactions
• Users perceive immediate feedback
• Smooth, natural feel
• Target for competitive advantage

Needs Improvement: 200-500 milliseconds

• Perceptible delay
• Still functional but sluggish
• Users may notice lag
• Optimization should be prioritized

Poor: >500 milliseconds

• Significant unresponsiveness
• Users may click multiple times
• Perceived as broken
• Critical optimization required

Why INP Threshold is Higher

INP’s 200ms “good” threshold (vs FID’s 100ms) reflects that INP measures the complete interaction cycle, not just input delay.

Justification:

• INP includes processing time and presentation delay
• Complete interaction naturally takes longer than input delay alone
• 200ms represents perceptual threshold for “instant” feedback
• Aligns with human perception research on responsiveness

Threshold Impact on Pass Rates

FID Pass Rates:

• 93% of mobile sites: Good FID (≤100ms)
• 96% of desktop sites: Good FID

INP Pass Rates:

• 65% of mobile sites: Good INP (≤200ms)
• ~70% of desktop sites: Good INP

The 28% Gap: The difference between 93% (FID) and 65% (INP) pass rates reveals that nearly one-third of sites appearing “responsive” under FID actually deliver poor user experiences.

Measuring at 75th Percentile

Google evaluates Core Web Vitals at the 75th percentile of real user experiences.

What This Means: For a page to pass INP, 75% of user visits must have INP ≤200ms. If 26% of visits have INP >200ms, the page fails.

Practical Impact:

• Can’t ignore mobile performance
• Must optimize for diverse conditions
• Real-world networks and devices matter
• Synthetic “perfect” tests insufficient

See how we achieved 608% increase in organic traffic through comprehensive performance optimization.

---

How to Measure INP and FID

Accurate measurement is critical for understanding performance and tracking optimization progress.

Measuring INP

1. Google PageSpeed Insights

The easiest way to see INP is through PageSpeed Insights, which displays data from the Chrome User Experience Report (CrUX).

How to Use:

1. Go to PageSpeed Insights
2. Enter your URL
3. Review “Field Data” section for real-user INP
4. Check “Lab Data” for simulated testing insights

What You’ll See:

• INP value at 75th percentile
• Pass/fail status (good/needs improvement/poor)
• Mobile and desktop scores separately
• Historical trend data

2. Google Search Console

Search Console includes INP in Core Web Vitals reports since March 12, 2024.

How to Access:

1. Open Google Search Console
2. Navigate to “Core Web Vitals” under “Experience”
3. Review “Mobile” and “Desktop” tabs
4. Click URL groups to see affected pages

Benefits:

• Official Google data
• URL-level breakdown
• Historical tracking
• Issue identification

3. Chrome User Experience Report (CrUX)

CrUX provides the official dataset for Core Web Vitals, including INP.

Access Methods:

• PageSpeed Insights (easiest)
• CrUX API
• CrUX Dashboard on Looker Studio
• BigQuery (for advanced analysis)

Important Note: Your website must meet eligibility criteria for CrUX inclusion (sufficient traffic volume).

4. Real User Monitoring (RUM) Providers

RUM solutions collect field data directly from your users:

Popular RUM Tools:

• SpeedCurve
• DebugBear
• New Relic
• DataDog
• Sentry

Advantages:

• More detailed data than CrUX
• Custom segmentation
• Real-time monitoring
• Interaction-level insights

5. Web Vitals JavaScript Library

For custom implementation, use Google’s web-vitals library:

import {onINP} from 'web-vitals';

onINP(console.log);
// Logs: {name: "INP", value: 245, rating: "needs-improvement"}

6. Chrome DevTools

Test INP in lab environment using Chrome DevTools:

1. Open DevTools (F12)
2. Go to “Performance” panel
3. Record while interacting with page
4. Analyze INP component breakdown

What DevTools Shows:

• Input delay duration
• Processing time
• Presentation delay
• Visual timeline of interaction

Measuring FID (For Historical Comparison)

Note: FID was removed from most tools on March 12, 2024, but historical data may still be available.

1. Historical CrUX Data

Access past FID metrics through:

• CrUX BigQuery dataset (historical data preserved)
• PageSpeed Insights (data before March 2024)
• Search Console (archived reports)

2. RUM Providers

Most RUM tools maintained FID tracking and can provide historical comparisons.

3. Total Blocking Time (TBT) as Proxy

For lab testing, TBT served as FID’s proxy metric:

• Available in Lighthouse
• Available in PageSpeed Insights lab data
• Correlates with FID (though not identical)

Best Practices for Measurement

1. Use Multiple Data Sources

Don’t rely on single tool:

• CrUX/Search Console for official Google data
• RUM for detailed insights
• Lab testing for debugging
• Combine for complete picture

2. Segment Data Properly

Analyze separately:

• Mobile vs desktop
• Geographic regions
• User segments
• Traffic sources

3. Monitor Continuously

Set up ongoing tracking:

• Weekly Search Console reviews
• RUM alerts for degradation
• Monthly trend analysis
• Before/after optimization comparison

4. Focus on Real Users

Prioritize field data over lab:

• Real networks and devices
• Actual user behavior
• Geographic distribution
• Diverse conditions

Explore our performance audit services for comprehensive Core Web Vitals analysis.

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INP Optimization Strategies for Developers

Improving INP requires addressing all three components: input delay, processing time, and presentation delay.

Strategy 1: Reduce Input Delay

Input delay occurs when the main thread is busy and cannot respond immediately to user interaction.

Optimization Techniques:

Break Up Long Tasks

Long JavaScript tasks (>50ms) block the main thread. Split them into smaller chunks:

// BAD: Long blocking task
function processItems(items) {
  items.forEach(item => heavyComputation(item));
}

// GOOD: Chunked with yielding
async function processItems(items) {
  for (const item of items) {
    heavyComputation(item);
    // Yield to main thread
    await new Promise(resolve => setTimeout(resolve, 0));
  }
}

Use Web Workers

Offload heavy processing to background threads:

// Main thread
const worker = new Worker('processor.js');
worker.postMessage(data);
worker.onmessage = (e) => updateUI(e.data);

// processor.js (Web Worker)
self.onmessage = (e) => {
  const result = heavyComputation(e.data);
  self.postMessage(result);
};

Defer Non-Critical JavaScript

Load non-essential scripts asynchronously:

<!-- GOOD: Deferred loading -->
<script src="analytics.js" defer></script>
<script src="chat-widget.js" async></script>

Optimize Third-Party Scripts

Third-party code often causes input delays:

• Load asynchronously
• Delay until after user interaction
• Use facade pattern for heavy widgets
• Monitor and remove unused scripts

Example – Lazy Load Chat Widget:

let chatLoaded = false;

document.addEventListener('scroll', () => {
  if (!chatLoaded && window.scrollY > 500) {
    loadChatWidget();
    chatLoaded = true;
  }
}, { once: true, passive: true });

Strategy 2: Optimize Processing Time

Processing time is how long event handlers take to execute.

Optimization Techniques:

Simplify Event Handlers

Keep callback logic lightweight:

// BAD: Heavy processing in handler
button.addEventListener('click', () => {
  const result = complexCalculation();
  const formatted = formatData(result);
  const validated = validateResult(formatted);
  updateDOM(validated);
});

// GOOD: Defer heavy work
button.addEventListener('click', () => {
  requestIdleCallback(() => {
    const result = complexCalculation();
    const formatted = formatData(result);
    const validated = validateResult(formatted);
    updateDOM(validated);
  });
});

Debounce/Throttle Rapid Events

For events that fire frequently:

// Debounce for search input
const debouncedSearch = debounce((query) => {
  performSearch(query);
}, 300);

input.addEventListener('input', (e) => {
  debouncedSearch(e.target.value);
});

// Throttle for scroll events
const throttledScroll = throttle(() => {
  updateScrollPosition();
}, 100);

window.addEventListener('scroll', throttledScroll);

Avoid Forced Synchronous Layouts

Don’t trigger layout recalculation inside loops:

// BAD: Forces layout in loop (layout thrashing)
elements.forEach(el => {
  const height = el.offsetHeight; // Forces layout
  el.style.height = height + 10 + 'px'; // Invalidates layout
});

// GOOD: Batch reads, then batch writes
const heights = elements.map(el => el.offsetHeight);
elements.forEach((el, i) => {
  el.style.height = heights[i] + 10 + 'px';
});

Optimize JavaScript Execution

• Minimize DOM access
• Cache DOM references
• Use efficient algorithms
• Avoid unnecessary calculations

Code Splitting

Load only necessary JavaScript for each route:

// Next.js dynamic import example
const HeavyComponent = dynamic(() => import('./HeavyComponent'), {
  loading: () => <Spinner />
});

Strategy 3: Reduce Presentation Delay

Presentation delay is time from handler completion to visual update.

Optimization Techniques:

Minimize DOM Size

Large DOMs slow rendering:

Targets:

• Keep DOM under 1,500 nodes
• Limit depth to 32 levels
• Avoid deeply nested structures

CSS Content Visibility

Lazy render off-screen content:

.lazy-section {
  content-visibility: auto;
  contain-intrinsic-size: 0 500px;
}

Optimize CSS Rendering

• Reduce CSS complexity
• Avoid expensive properties (shadows, filters on large areas)
• Use transform and opacity for animations
• Minimize reflows/repaints

Virtualize Long Lists

Don’t render all items at once:

// Use virtualization libraries
import { FixedSizeList } from 'react-window';

<FixedSizeList
  height={600}
  itemCount={10000}
  itemSize={35}
>
  {Row}
</FixedSizeList>

Batch DOM Updates

Group changes together:

// BAD: Multiple reflows
el.style.width = '100px';
el.style.height = '100px';
el.style.border = '1px solid black';

// GOOD: Single reflow
el.style.cssText = 'width: 100px; height: 100px; border: 1px solid black';

Strategy 4: Framework-Specific Optimizations

React Optimization:

// Use transitions for non-urgent updates
import { startTransition } from 'react';

function handleClick() {
  startTransition(() => {
    setCount(count + 1);
  });
}

// React 19: Activity mode for hidden content
<Activity mode="hidden">
  <Sidebar />
</Activity>

Next.js Optimization:

// Server Components reduce client JavaScript
// app/page.tsx
export default async function Page() {
  const data = await getData();
  return <ClientComponent data={data} />;
}

// Priority loading for LCP images
<Image
  src="/hero.jpg"
  priority
  width={1200}
  height={600}
/>

Strategy 5: Monitor and Iterate

Continuous Improvement:

1. Establish baseline INP measurement
2. Implement targeted optimizations
3. Measure impact with real user data
4. Identify remaining bottlenecks
5. Repeat optimization cycle

Key Metrics to Track:

• INP 75th percentile
• Input delay breakdown
• Processing time breakdown
• Presentation delay breakdown
• Interaction-specific latencies

Check our e-commerce growth services for conversion-focused performance optimization.

---

SEO Impact: How INP Affects Rankings

Understanding INP’s influence on search rankings helps prioritize optimization efforts appropriately.

INP as a Ranking Factor

Since March 12, 2024, INP has been part of Google’s Page Experience ranking signals.

Official Status: INP is a confirmed Core Web Vitals metric and contributes to the page experience ranking system.

Important Context: Google’s John Mueller clarified: <cite index=”42-1″>”This Core Web Vital metric change from FID to INP will have very little to no impact on your search rankings. I will say that again, this change will have almost zero impact on how your site ranks in search.”</cite>

What This Means:

• Core Web Vitals are ranking factors
• But they’re not dominant ranking factors
• Content quality and relevance matter far more
• INP won’t make your rankings “jump up”

Realistic SEO Expectations

Direct Ranking Impact: Minimal

According to Google, even perfect Core Web Vitals scores won’t dramatically improve rankings.

Google’s Martin Splitt stated: <cite index=”42-1″>”Good stats within the Core Web Vitals report in Search Console or third-party Core Web Vitals reports don’t guarantee good rankings.”</cite>

Where INP Matters for SEO:

1. Competitive Differentiation

When content quality is equal, better page experience provides an advantage. Industry data suggests Core Web Vitals account for approximately 25-30% of ranking weight in competitive queries.

2. Mobile Search

With mobile-first indexing, mobile INP performance particularly matters. 65% pass rate on mobile INP means good scores provide competitive differentiation.

3. User Experience Signals

Poor INP indirectly hurts SEO through:

• Higher bounce rates
• Lower time on site
• Reduced pages per session
• Fewer conversions
• Lower engagement metrics

4. Page Experience Algorithm

INP contributes to overall page experience scoring alongside:

• LCP (Largest Contentful Paint)
• CLS (Cumulative Layout Shift)
• HTTPS security
• Mobile-friendliness
• No intrusive interstitials

Business Impact vs SEO Impact

While direct ranking impact is modest, business impact is substantial.

Conversion Impact:

• Sites moving from poor to good Core Web Vitals see 8-15% visibility increase
• Improved INP correlates with higher conversion rates
• Better responsiveness reduces cart abandonment
• Faster interactions improve user satisfaction

User Retention:

• 53% of mobile users abandon sites taking >3 seconds to load
• Poor INP contributes to perceived slowness
• Users unlikely to return to unresponsive sites
• Brand perception suffers with poor performance

Competitive Analysis: Only 35-58% of sites in most industries meet all Core Web Vitals thresholds, meaning optimization creates competitive advantage.

SEO Strategy Recommendations

Don’t Obsess Over INP for Rankings

Focus on content quality, relevance, and authority first. Perfect INP won’t save poor content.

Do Optimize for User Experience

Improve INP because it enhances actual user experience, not just for marginal ranking gains.

Balance Effort Appropriately

• Getting from poor to good: High priority
• Getting from good to perfect: Low SEO priority
• Focus on biggest wins first

Monitor Holistically

Track INP alongside:

• Bounce rate
• Time on site
• Conversion rate
• Revenue per visitor
• User engagement

View our successful from struggling website to thriving online presence case study for holistic optimization approach.

---

Common INP Optimization Mistakes to Avoid

Developers and SEOs frequently make these errors when optimizing INP. Avoid them for more effective improvement.

Mistake 1: Optimizing for Lab Data Only

Why It’s Problematic: Lab testing doesn’t reflect real-world conditions with diverse networks, devices, and user behaviors.

Correct Approach:

• Prioritize field data (CrUX, RUM)
• Use lab testing for debugging only
• Test on real devices and networks
• Monitor 75th percentile of real users

Implementation:

// Collect real user INP data
import {onINP} from 'web-vitals';

onINP((metric) => {
  // Send to analytics
  sendToAnalytics({
    name: 'INP',
    value: metric.value,
    rating: metric.rating,
    page: window.location.pathname
  });
});

Mistake 2: Ignoring Mobile Performance

Why It’s Problematic: Mobile devices have less processing power and slower networks, making INP scores 35.5% worse on average than desktop.

Correct Approach:

• Optimize mobile-first
• Test on mid-range devices, not flagship phones
• Consider slow 3G networks
• Monitor mobile-specific metrics

Mobile Optimization Focus:

• Reduce JavaScript payload for mobile
• Implement progressive enhancement
• Use responsive images appropriately
• Test on actual mobile devices

Mistake 3: Adding More JavaScript to Fix JavaScript Problems

Why It’s Problematic: Loading additional libraries or frameworks to “optimize” performance often makes INP worse.

Example of This Trap:

// BAD: Adding heavy library to "optimize"
import heavyOptimizationLib from 'massive-lib'; // 150KB
heavyOptimizationLib.optimizePerformance();

Correct Approach:

• Remove unnecessary JavaScript first
• Use vanilla JavaScript where possible
• Audit and eliminate unused dependencies
• Lazy load non-critical functionality

Mistake 4: Not Measuring Component Breakdown

Why It’s Problematic: Without knowing which component (input delay, processing, or presentation) causes poor INP, optimization efforts are guesswork.

Correct Approach: Use Chrome DevTools to analyze INP components:

1. Record interaction in Performance panel
2. Identify which phase is slowest
3. Target specific optimization
4. Verify improvement

Component-Specific Fixes:

• High input delay → Reduce main thread work
• High processing time → Optimize event handlers
• High presentation delay → Reduce rendering work

Mistake 5: Focusing on Average Instead of Percentiles

Why It’s Problematic: Google measures at 75th percentile. Average values mask poor experiences for significant user segments.

Correct Approach:

• Monitor 75th and 95th percentiles
• Identify worst-case scenarios
• Optimize for slowest experiences
• Don’t celebrate low averages

Measurement Example:

• Average INP: 180ms (looks good)
• 75th percentile INP: 420ms (fails threshold)
• Need to fix: High percentile, not average

Mistake 6: Neglecting Third-Party Scripts

Why It’s Problematic: Third-party scripts (analytics, ads, chat widgets) often cause the worst INP violations but are rarely optimized.

Correct Approach:

• Audit all third-party scripts
• Load non-critical scripts asynchronously
• Implement facade pattern for heavy widgets
• Set performance budgets for third parties
• Remove unused tracking codes

Third-Party Budget Strategy:

// Set maximum third-party impact
const THIRD_PARTY_BUDGET_MS = 100;

// Monitor and enforce
if (thirdPartyTime > THIRD_PARTY_BUDGET_MS) {
  alert('Third-party budget exceeded');
}

Mistake 7: Over-Optimizing at the Expense of Functionality

Why It’s Problematic: Stripping features to improve INP can hurt user experience and business goals.

Correct Approach:

• Balance performance with functionality
• Optimize implementation, not features
• Provide value to users first
• Use progressive enhancement

Decision Framework:

1. Is this feature valuable to users?
2. Can we optimize implementation?
3. Can we defer loading?
4. If removal necessary, what’s the impact?

Mistake 8: Making Assumptions Without Data

Why It’s Problematic: Assumptions about what causes poor INP often lead to wasted effort on wrong optimizations.

Correct Approach:

• Measure before optimizing
• Identify actual bottlenecks with data
• Test hypotheses with A/B testing
• Verify improvements with metrics

Data-Driven Process:

1. Establish baseline INP
2. Identify slowest interactions
3. Analyze component breakdown
4. Implement targeted fix
5. Measure impact
6. Iterate based on results

Learn from our 375% increase in organic traffic case study showing proper optimization prioritization.

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Tools for Monitoring INP Performance

Effective INP optimization requires the right measurement and monitoring tools.

Google’s Official Tools

1. Google Search Console

Best For: Official Google perspective, site-wide health monitoring

Features:

• URL-level Core Web Vitals reports
• Mobile and desktop segmentation
• Historical trend data
• Affected URLs grouping

How to Use:

1. Access Core Web Vitals report
2. Review poor, needs improvement, good URLs
3. Click URL groups for details
4. Prioritize pages by traffic/importance

2. PageSpeed Insights

Best For: Quick page analysis, CrUX data access

Features:

• Field data from CrUX (75th percentile)
• Lab data from Lighthouse
• Specific optimization recommendations
• Mobile and desktop analysis

Limitations:

• Requires sufficient CrUX data
• No historical tracking
• Single-page analysis

3. Chrome User Experience Report (CrUX)

Best For: Comprehensive real-user data

Access Methods:

• CrUX Dashboard (Looker Studio)
• CrUX API
• BigQuery dataset
• Via PageSpeed Insights

Advantages:

• Official Google dataset
• 28-day rolling average
• Origin and URL-level data
• Free and comprehensive

Real User Monitoring (RUM) Solutions

1. DebugBear

Features:

• Real-time INP monitoring
• Interaction-level breakdown
• Component analysis (input/processing/presentation)
• Custom alerting

Best For: Detailed INP debugging

2. SpeedCurve

Features:

• Continuous monitoring
• Performance budgets
• Competitive benchmarking
• Synthetic and RUM data

Best For: Enterprise monitoring

3. Sentry

Features:

• Error tracking + performance
• INP attribution to specific code
• User session replay
• Integration with development workflow

Best For: Developer teams

4. New Relic / DataDog

Features:

• Application performance monitoring
• Full-stack observability
• Custom dashboards
• Business metrics correlation

Best For: Large-scale applications

Developer Tools

1. Chrome DevTools

Best For: Local testing and debugging

How to Use:

1. Open DevTools (F12)
2. Go to Performance panel
3. Record while interacting
4. Analyze INP component breakdown

Features:

• Visual timeline
• Component breakdown
• Long task identification
• Frame rendering analysis

2. Lighthouse

Best For: Lab testing, CI/CD integration

Features:

• Automated audits
• Performance scoring
• Specific recommendations
• Command-line interface

Note: Lighthouse simulates interactions, doesn’t capture real INP but provides related insights.

3. Web Vitals Extension

Best For: Quick real-time monitoring

Features:

• Browser toolbar display
• Real-time metric updates
• All Core Web Vitals
• Minimal setup

Installation: Available in Chrome Web Store

Monitoring Best Practices

1. Multi-Tool Approach

Combine tools for comprehensive view:

• Google Search Console (official data)
• RUM provider (detailed insights)
• Chrome DevTools (debugging)
• Lighthouse (CI/CD integration)

2. Set Up Alerts

Configure notifications for:

• INP regression
• New pages failing threshold
• Specific URL problems
• Traffic-weighted degradation

3. Create Dashboards

Track key metrics:

• INP 75th percentile
• Good/needs improvement/poor distribution
• Mobile vs desktop comparison
• Trend over time
• Business metric correlation

4. Regular Review Cadence

• Daily: RUM alerts and critical issues
• Weekly: Trend analysis and new problems
• Monthly: Comprehensive audits
• Quarterly: Strategic optimization planning

5. Segment Appropriately

Analyze separately:

• Page types (homepage, product, category)
• Device types (mobile, desktop, tablet)
• Traffic sources
• User segments
• Geographic regions

Explore our SEO services for comprehensive technical optimization and monitoring.

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FAQ

Discover our marketing automation services to enhance user experience alongside technical optimization.

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Conclusion

The transition from FID to INP represents a fundamental shift in how Google evaluates website responsiveness. While FID measured only the first interaction’s input delay—allowing 93% of sites to pass—INP’s comprehensive measurement of all interactions reveals the truth: only 65% of sites deliver genuinely responsive experiences.

Key Takeaways:

• INP replaced FID on March 12, 2024, becoming the official Core Web Vitals metric for responsiveness
• INP is more comprehensive, measuring complete interaction latency (input delay + processing + presentation) for all interactions, not just the first
• The 200ms threshold is achievable but requires strategic optimization of JavaScript execution, event handlers, and rendering performance
• SEO impact is modest but real—focus on INP for user experience benefits rather than expecting dramatic ranking improvements
• Mobile optimization is critical since INP scores are 35.5% worse on mobile devices on average
• Continuous monitoring is essential using Google Search Console, RUM providers, and Chrome DevTools for ongoing performance health

For developers and SEOs, INP optimization isn’t optional—it’s a fundamental aspect of delivering quality user experiences in 2025 and beyond. The gap between FID pass rates (93%) and INP pass rates (65%) proves that most sites have significant work ahead.

Start by measuring your current INP using Google Search Console and PageSpeed Insights. Identify your worst interactions using Chrome DevTools. Focus on reducing JavaScript execution time, optimizing event handlers, and minimizing rendering work. Monitor progress with real user data and iterate based on measurable improvements.

Ready to optimize your website’s INP? Our team at Stakque specializes in Core Web Vitals optimization, technical SEO, and performance-first development. Contact us today to discuss your specific performance challenges and develop a customized optimization strategy.

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This article was last updated on December 17, 2025, to reflect the most current information about INP optimization and Core Web Vitals standards.