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Mastering Google’s INP Metric: Optimize Site Performance with Ranklogs Site Auditor


As a website owner, optimizing for performance should be high on your list of priorities for boosting your Google rank. One of the most important core web vitals is the INP, or Interaction to Next Paint

On March 12, 2024, Interaction to Next Paint replaced the First Input Delay (FID) as one of the core web vitals. The term is technical, and understanding INP can help you be more objective in performance optimization. 

In this guide on Google INP, we explore what it is and how you can use Ranklogs Site Auditor to optimize INP. 


What is INP?

Interaction to Next Paint (INP) is a modern performance metric designed to measure the responsiveness of web applications by tracking the time from a user’s interaction (like clicks, taps, or key presses) to the web page’s visual update or next paint. This metric provides a detailed and user-centric view of the interactive responsiveness across a page’s entire lifecycle, not just at the start.

INP captures the delay for processing and rendering the most significant user interactions. It focuses on the longest interaction latency that a user experiences, which can reveal the impact of the most problematic parts of the web application.

Calculation of INP:

  1. Event Triggering: INP starts measuring when a user initiates an interaction. This could be any discrete action such as a mouse click, touch, or keyboard event.
  2. Response Time Measurement: The metric measures the time it takes the browser to start processing this interaction to the point where the visual response is observable on the screen.
  3. Long Task Influence: INP is significantly affected by long tasks in JavaScript. A long task is any task that blocks the main thread for more than 50 milliseconds, delaying the browser’s ability to respond to user inputs.
  4. Worst-case Interaction: Unlike other metrics that might average the responsiveness, INP identifies and reports the worst-case response time during a user session, giving developers insight into the most significant user-perceived delays.

Why INP Over Other Metrics?

While metrics like First Input Delay (FID) measure the response time for the first user interaction, they do not account for any interaction that occurs after the page has loaded. INP extends this by continuously measuring interactions, providing a more complete picture of the ongoing user experience during a session. It helps developers understand the worst delays users might face, which is crucial for optimizing complex applications that require frequent user interactions.

Tools for Measuring INP:

Developers can measure INP using several tools:

  • Field Tools: Chrome User Experience Report (CrUX) provides real user monitoring data, including INP measurements.
  • Lab Tools: Synthetic monitoring tools like Lighthouse and WebPageTest can simulate user interactions in controlled environments to estimate INP under various conditions.
  • Browser Developer Tools: Modern browsers have built-in performance panels that track INP, among other metrics. These panels allow developers to see these metrics in real time as they interact with the application.

Importance of INP

Interaction to Next Paint (INP) is emerging as one of the most crucial metrics for understanding and improving user experience on the web. As the digital landscape becomes more interactive, the responsiveness of web applications directly impacts how users perceive and interact with content. Here are detailed insights into why INP is so important:

Enhanced User Experience:

  • Perceived Performance: INP measures how quickly a website responds to user inputs, which is a primary factor in how users perceive a site’s performance. A lower INP indicates that the site is more responsive, making it feel faster and more fluid to the user.
  • Reduced Frustration and Increased Engagement: Slow responsiveness leads to user frustration, which can increase bounce rates and reduce overall engagement. By optimizing INP, developers can create a smoother experience that keeps users engaged longer and more deeply with the content.

Impact on SEO and Conversion Rates:

  • Google’s Core Web Vitals: INP is part of Google’s Core Web Vitals, a set of metrics Google uses to assess the quality of user experience on a website. A good INP score can enhance a site’s search engine ranking, making it more visible to potential visitors.
  • Conversion Impact: Studies have shown that sites with better responsiveness and faster interaction times have higher conversion rates. For example, Vodafone improved sales by 8%, improving their core web vitals.

Long-term Business Benefits:

  • Brand Perception: Fast and responsive sites are often perceived as more professional and reliable. Improving INP can enhance the brand’s image and customer satisfaction.
  • Cost Efficiency: By focusing on INP, companies can reduce the need for more drastic overhauls of their websites by addressing issues that directly impact user experience. This targeted optimization can lead to better resource allocation and lower development costs.

Examples and Case Studies:

  • E-commerce Success: Ebay focused on improving its INP by 100ms, and the adjustment led to a noticeable improvement in user retention during checkout, resulting in a 0.5% increase in add-to-cart transactions.

Strategic Importance in Development:

  • Feedback for Development: Regular monitoring and optimizing for INP provide actionable feedback for developers, helping them understand how updates and changes affect user experience.
  • Prioritization of Resources: By understanding the worst interaction latencies through INP measurements, teams can prioritize the most critical areas for improvement, ensuring that resources are smartly allocated to maximize user satisfaction.

How is INP Calculated?

INP is calculated by measuring the response times of various user interactions during a session and identifying the worst-case interaction latency. This metric considers the longest delay experienced by users, providing a clear picture of the worst moments of interaction delay they might face. Developers can measure INP using Chrome User Experience Report, Lighthouse, and other performance monitoring software that supports new web vitals.

Optimizing for INP

Improving Interaction with Next Paint (INP) is essential for creating a responsive, user-friendly website. Here are several targeted strategies that can help developers optimize INP effectively:

  1. Optimize JavaScript Execution:
  • Break Down Long Tasks: Long tasks take more than 50 milliseconds and can delay the processing of user interactions. Break these tasks into smaller chunks using techniques like asynchronous JavaScript, web workers, or by leveraging modern JavaScript frameworks that automatically optimize rendering cycles.
  • Use RequestIdleCallback: This API allows developers to schedule background tasks only when the browser is idle, ensuring that these tasks do not interfere with critical updates and user interactions.
  • Defer Non-Essential Scripts: Move scripts that are not critical to the initial user interaction towards the end of the loading sequence or load them asynchronously to avoid blocking the main thread.
  1. Enhance Resource Loading:
  • Prioritize Critical Resources: Utilize the preload attribute to load key resources early. This can be particularly beneficial for scripts and stylesheets crucial for initial user interactions.
  • Optimize Asset Delivery: Compress images, employ modern image formats like WebP, and utilize adaptive loading techniques to serve different assets based on the user’s device and connection type.
  • Implement Efficient Caching: Use service workers and cache strategies to reuse resources efficiently across visits, reducing the load on the server and speeding up the interaction readiness.
  1. Improve Interaction Readiness:
  • Optimize Event Handlers: Simplify and optimize the code of event handlers to execute more quickly. Throttling and debouncing user interactions can also prevent excessive function executions that could degrade performance.
  • Precompute Results: Whenever possible, compute expected results in advance (during idle times) so that interactions can be processed faster when they occur.
  • Utilize the CSS Containment Property: This property tells the browser that certain elements are isolated from others in the DOM, which can reduce the amount of rendering work needed during interactions.
  1. Monitor and Analyze performance:
  • Use Performance Monitoring Tools: Tools like Lighthouse, WebPageTest, and Chrome DevTools provide insights into a site’s performance, specifically its score on the INP metric. These tools can help identify bottlenecks and test the effectiveness of optimizations.
  • Implement Real User Monitoring (RUM): RUM tools capture actual user interaction data, providing insights into how users experience the site across different devices and network conditions. This data is invaluable for understanding and improving INP in real-world scenarios.
  1. Continuous Testing and Optimization:
  • A/B Testing: Implement A/B testing to compare different optimization strategies and their effects on INP. This can help determine the most effective tactics for specific user bases.
  • Feedback Loop: Establish a feedback loop where performance data continuously informs development practices. This ensures that optimizations lead to measurable improvements in user experience.

How Ranklogs Site Auditor Can Help Optimize for Google INP

Ranklogs Site Auditor is an integral tool for comprehensive site performance evaluation and error detection. It provides website owners and developers with the necessary insights and actionable recommendations to enhance their site’s interaction responsiveness, directly impacting the Interaction to Next Paint (INP) metric. Here’s how Ranklogs Site Auditor can be instrumental:

  1. Comprehensive Performance Analysis:
  • Detailed Audits: Ranklogs Site Auditor thoroughly assesses a website’s overall health, including performance metrics like INP. It identifies and reports on elements that contribute to interaction delays, offering a granular view of factors affecting responsiveness.
  • Visualization of Metrics: The auditor presents data in an easy-to-understand format, including visualizations that pinpoint specific performance bottlenecks. This helps developers identify critical issues that need immediate attention.
  1. Error Detection and Recommendations:
  • Automated Error Spotting: The tool scans the entire website to detect errors and inefficiencies that could impair INP, such as heavy scripts, unoptimized images, and excessive DOM size.
  • Actionable Fixes: After identifying issues, the Ranklogs Site Auditor provides actionable recommendations on resolving these problems. For example, it might suggest minifying CSS and JavaScript files, leveraging browser caching, or removing render-blocking resources.
  1. Optimization Suggestions for Faster Interactions:
  • Code Optimization: Ranklogs provides specific suggestions for optimizing code structures and implementation, including refactoring JavaScript to be more efficient and less obstructive to the main thread.
  • Resource Loading Strategies: The tool recommends strategies for prioritizing and loading critical resources first, ensuring that the most important content is interactable as soon as possible.
  1. Real-time Monitoring and Alerts:
  • Continuous Monitoring: Ranklogs Site Auditor offers real-time monitoring capabilities, allowing users to track their site’s performance as changes are made and understand how these changes affect INP.
  • Alert System: It features an alert system that notifies developers and site owners if any new performance issues could negatively impact INP, ensuring that potential problems can be addressed promptly.
  1. User Experience Enhancement:
  • Focus on User-Centric Metrics: By focusing on metrics that directly affect user experience, such as INP, Ranklogs helps ensure that optimizations contribute to a tangible improvement in how users interact with the site.
  • Support for Mobile Optimization: Since mobile users often experience longer interaction times, Ranklogs Site Auditor includes tools and recommendations tailored for mobile optimization, which is crucial for maintaining a good INP score on all devices.


Any business owner with an online presence must understand how crucial optimizing Google’s INP metric is. Enhancing site performance and user experience depends on measuring and improving the responsiveness of web interactions. Tools like Ranklogs Site Auditor can help site owners achieve better engagement and conversion rates and gain a competitive edge in SEO by optimizing INP.