perf_agent_report_experiment_2.md

Interaction to Next Paint (INP) Optimization Report

This report summarizes the common causes of poor Interaction to Next Paint (INP) scores and provides actionable insights for optimization. INP measures the time between a user interaction and the next visual update on the page, reflecting a website's responsiveness. As of March 2024, INP is a Core Web Vital, directly impacting search performance. A good INP score is less than 200 milliseconds; scores over 500 milliseconds are considered poor and can negatively affect search rankings Measure And Optimize Interaction to Next Paint (INP).

Summary of Findings

The primary causes of poor INP scores are related to excessive CPU processing, long tasks, rendering delays, and unoptimized JavaScript execution. Optimizing website code, minimizing long tasks, and employing asynchronous techniques are crucial for improving INP and ensuring a responsive user experience.

Analysis of Search Results

Key Factors Contributing to Poor INP

1. Excessive CPU Processing: High CPU usage on a page is a major contributor to poor INP, often stemming from inefficient website code or third-party scripts. Minimizing CPU processing is crucial for improving INP Measure And Optimize Interaction to Next Paint (INP).
2. Long Tasks: Long tasks, especially those occurring just before the DOM Content Loaded event or within click event handlers, significantly contribute to input delay and poor INP scores Understanding and Improving Interaction to Next Paint (INP). A long task was originally part of the click event handler, but using setTimeout to schedule it into its own separate task allows the browser to paint before the Long Task executes Understanding and Improving Interaction to Next Paint (INP).
3. Rendering Delays: Rendering delays, often influenced by scripts, directly impact INP by increasing the time between user input and the resulting UI updates Measure And Optimize Interaction to Next Paint (INP). The Long Animation Frames (LoAF) API reports what scripts are contributing to rendering delays Measure And Optimize Interaction to Next Paint (INP).
4. JavaScript Execution: Unoptimized JavaScript execution is a significant cause of poor INP. Minimizing CPU processing and running code asynchronously can help Measure And Optimize Interaction to Next Paint (INP).

Tools and Techniques for INP Optimization

• Chrome DevTools Performance Profiler: This tool shows the INP component breakdown and their timings when hovering over an interaction Measure And Optimize Interaction to Next Paint (INP). The interaction block changes to stripes after 200 ms, indicating the task is taking longer than what Google considers a good INP score Measure And Optimize Interaction to Next Paint (INP).
• Long Animation Frames (LoAF) API: This API reports what scripts are contributing to rendering delays, which is especially useful when a rendering delay occurs at the time when a user interacts with the page Measure And Optimize Interaction to Next Paint (INP).

Analysis of Results

Insights and Observations

1. CPU Processing: Excessive CPU processing on the page is a primary cause of poor INP. This can stem from inefficient website code or the impact of third-party scripts.
2. Long Tasks: Long tasks, especially those occurring just before the DOM Content Loaded event or within click event handlers, significantly contribute to input delay and, consequently, poor INP scores.
3. Rendering Delays: Rendering delays, influenced by scripts, directly impact INP by increasing the time between user input and the resulting UI updates.
4. JavaScript Execution: JavaScript execution is a significant cause of poor INP. Minimizing CPU processing and running code asynchronously can help. Long tasks, often related to deferred and module scripts executing before DOM Content Loaded, can also contribute to input delay.
5. Rendering Bottlenecks: Rendering bottlenecks contribute to poor INP. INP evaluates the entire response process, including content rendering and visual changes on the screen. The Long Animation Frames (LoAF) API reports what scripts are contributing to rendering delays.
6. User Input and UI Updates: INP measures the time between user input and UI updates, including input delay and presentation delay. Optimizing third-party scripts is also important.
7. Event Handlers and Long Tasks: Optimizing event handlers and breaking up long tasks are moderately complex but high-impact strategies. They require code refactoring and a good understanding of JavaScript execution but can significantly improve INP by preventing the main thread from being blocked for extended periods. Showing a loading indicator provides immediate user feedback, improving perceived performance while the task completes.
8. Layout Thrash: Reducing layout thrash is a moderately complex optimization with a potentially high impact. It involves careful management of DOM updates and style calculations to prevent unnecessary reflows and repaints. Using CSS transforms and opacity for animations can also improve rendering performance.
9. Asynchronous Techniques and Worker Offloading: Using asynchronous techniques and worker offloading is a complex but high-impact strategy. It requires restructuring code to perform heavy tasks in the background, preventing them from blocking the main thread and improving INP. This approach is particularly effective for data parsing and image processing.

Recommendations

1. Minimize CPU Processing:
   • Profile website code to identify and optimize inefficient code.
   • Review and optimize or remove unnecessary third-party scripts.
2. Manage Long Tasks:
   • Break up long tasks into smaller, asynchronous tasks using techniques like setTimeout or requestIdleCallback.
   • Defer non-critical scripts to reduce the impact of long tasks occurring before the DOM Content Loaded event.
3. Optimize Rendering:
   • Use the Long Animation Frames (LoAF) API to identify scripts causing rendering delays.
   • Reduce layout thrash by batching DOM updates and using CSS transforms for animations.
4. Improve JavaScript Execution:
   • Minimize CPU processing by optimizing JavaScript code.
   • Run code asynchronously to prevent blocking the main thread.
5. Monitor and Measure:
   • Use Chrome DevTools Performance Profiler to monitor INP components and timings.
   • Continuously measure and monitor INP to identify and address regressions.
6. Optimize Event Handlers:
   • Keep event handlers light and defer heavy computations or data loads.
   • Show loading indicators to provide immediate user feedback while tasks complete.
7. Employ Asynchronous Techniques:
   • Use asynchronous techniques and worker offloading for heavy tasks like data parsing and image processing.

By implementing these recommendations, you can significantly improve INP scores, enhance user experience, and positively impact search rankings.