By Shad Super in Questions —

How Can Server Response Times Impact Interaction to Next Paint (INP), and What Server-Side Optimizations Can Improve INP Performance?

Summary

Interaction to Next Paint (INP) measures how quickly a page responds to user interactions and renders the next frame. Server response times critically impact INP by influencing how quickly server resources can be fetched and utilized. To improve INP performance, server-side optimizations like using a CDN, implementing server caching, optimizing databases, and reducing latency are essential.

Server-Side Optimizations

Content Delivery Network (CDN)

A CDN speeds up the delivery of static content by storing cached versions of resources on servers located closer to users. This reduces latency and improves server response times, thereby enhancing INP performance. For more information, see Why Performance Matters, 2023.

Server Caching

Server-side caching involves storing copies of pages or components that are frequently requested, allowing them to be served quicker without repeated database queries or page generation. This significantly reduces Time to First Byte (TTFB) and enhances INP. For detailed insights, refer to Time to First Byte (TTFB), 2020.

Database Optimization

Optimizing database queries and indexing can minimize latency and improve server response times. Streamlining queries and reducing unnecessary data retrieval ensure that resources are delivered faster, directly benefiting INP. Comprehensive guidelines can be found at Optimize CSS Delivery, 2022.

Efficient Asset Delivery

Preloading Resources

Using <link rel="preload"> helps load critical resources faster, improving the INP by ensuring essential assets are available without delay. Learn more about this technique at Preload Critical Assets, 2022.

Compression

Compressing images and text files using formats like WebP, Gzip, and Brotli reduces load times, thereby improving INP. Detailed methods can be reviewed at Enable Text Compression, 2021.

Responsive Images

Implementing responsive images with <srcset> and <sizes> attributes ensures that the appropriate image size is loaded based on the user's device, enhancing INP by reducing unnecessary loading times. For implementation guidelines, see Serve Responsive Images, 2023.

Minimize Render-Blocking Resources

CSS Optimization

Minifying CSS files and using <link rel="preload"> for critical styles help reduce render-blocking resources, leading to faster INP. Find more information at Optimize CSS Delivery, 2022.

JavaScript Defer/Async

Deferring non-critical JavaScript or loading it asynchronously minimizes the blocking of initial rendering, thus improving INP. For detailed methods, check out Defer Non-Critical JavaScript, 2023.

Critical Rendering Path

Inlining essential styles and scripts can reduce the critical rendering path, speeding up the time to visible content and enhancing INP. Detailed guidelines are available at Understanding the Critical Rendering Path, 2023.

Optimize Web Fonts

Preconnect

Using <link rel="preconnect"> establishes early connections to font providers, reducing load times and improving INP. Learn more at Preconnect and DNS Prefetch, 2022.

Font Display

Using the <font-display: swap> property ensures text is immediately displayed using fallback fonts until the custom fonts load, preventing invisible text, which improves INP. Detailed implementations can be found at Web Font Optimization, 2023.

Subsetting

Loading only the required font subsets or characters can reduce load times, directly impacting INP positively. For more details, refer to Web Font Best Practices, 2022.

Conclusion

Improving INP involves server-side optimizations, efficient asset delivery, minimizing render-blocking resources, and optimizing web fonts. A comprehensive approach to these best practices will significantly enhance INP and overall user experience.

References