By Shad Super in Questions —

What Are the Optimal Preconnect and Prefetch Strategies to Ensure Faster Resource Loading and Better Core Web Vitals Scores?

Summary

Optimal preconnect and prefetch strategies involve establishing early network connections with important third-party origins and prefetching key resources to ensure faster resource loading. Implementing these strategies can significantly improve the Core Web Vitals scores, leading to enhanced user experience and website performance.

Understanding Preconnect and Prefetch

Preconnect

<link rel="preconnect"> is an important resource hint that tells the browser to establish an early network connection to important third-party origins. This reduces the round-trip latency time and speeds up the resource fetching process [Uses rel=preconnect, 2020].

Prefetch

<link rel="prefetch"> provides a hint to the browser to fetch key resources in the background during idle time. This technique helps in loading these resources faster when needed, thus improving the page load time [Link Prefetch, 2020].

Optimal Preconnect Strategy

Preconnect to Important Third-party Origins

When using resources from third-party origins (like scripts, fonts, or styles), use <link rel="preconnect"> to establish an early connection. Doing this can significantly reduce the time taken to fetch these resources and improve site performance [Uses rel=preconnect, 2020].

Use Preconnect Sparingly

Remember that preconnect consumes additional data and CPU. Therefore, only preconnect to the most critical third-party origins to balance between performance and resource consumption [Prefetching, Preloading, Prebrowsing, 2022].

Optimal Prefetch Strategy

Prefetch Key Resources

Prefetch resources that will be needed for future navigations. This can significantly improve load times for these resources when they are needed, leading to smoother navigations and better user experience [Prefetching, 2020].

Use Prefetch with Caution

Be cautious when prefetching resources as idle time can vary across users, and prefetching too many resources can lead to bandwidth wastage. Prefer resources that are likely to be used in the next navigation and are not size-heavy [Link Prefetch, 2020].

Conclusion

Effectively implementing preconnect and prefetch techniques can significantly enhance the performance of a website and improve Core Web Vitals scores. Always keep a balanced approach considering both performance gains and resource consumption.

References