How to Fix Core Web Vital FID Issues in BigCommerce Store


In today’s rapidly evolving digital landscape, user experience has become the cornerstone of online success. Core Web Vitals, introduced by Google, are a set of user-centric metrics that play a pivotal role in determining the quality of user experience a website delivers. Among these, First Input Delay (FID) stands out as a critical metric that measures the responsiveness of a webpage when a user interacts with it. In this article, we’ll delve into the world of FID and guide you through the process of identifying and rectifying FID issues in your BigCommerce store.

Understanding Core Web Vitals

Core Web Vitals, as mentioned earlier, are a trio of essential metrics—Largest Contentful Paint (LCP), Cumulative Layout Shift (CLS), and First Input Delay (FID). These metrics collectively evaluate the loading performance, interactivity, and visual stability of a webpage. FID, specifically, focuses on gauging the responsiveness of a webpage to user interactions, such as clicks or taps.

Importance of FID

The significance of First Input Delay cannot be overstated. A high FID score implies that users are experiencing frustrating delays when attempting to interact with your website. This can lead to a surge in bounce rates and a decline in conversions. Addressing FID issues is not just an optimization tactic; it’s a crucial step toward retaining visitors and ensuring a seamless user experience.

Common Causes of FID Issues

JavaScript Execution

JavaScript, while powerful and versatile, can be a double-edged sword when it comes to FID. Poorly optimized or excessive JavaScript can significantly impact interactivity. Scripts that are executed in the main thread have the potential to block user interactions, resulting in noticeable delays.

Render-Blocking Resources

Large resources, such as high-resolution images or hefty stylesheets, have the potential to obstruct the rendering process. This obstruction can be a key contributor to elevated FID scores.

Third-Party Scripts

Scripts sourced from third-party services, such as analytics trackers or social media widgets, can introduce delays in interactivity. While these scripts may be beneficial for data collection and engagement, they should be managed judiciously to mitigate their impact on FID.

Tools to Measure FID

Google PageSpeed Insights

Google PageSpeed Insights is a powerful tool that provides a comprehensive analysis of your website’s performance. It offers valuable insights into FID scores and provides actionable recommendations for improvement.


WebPageTest, another indispensable tool, enables you to simulate user interactions and provides detailed metrics, including FID. It offers a deeper understanding of performance issues and allows for precise optimization strategies.

Strategies to Improve FID

[Pro Tip – You can check our BigCommerce speed optimization guide for in-depth optimization]

Minimize JavaScript

To combat FID issues stemming from JavaScript, it’s imperative to conduct a thorough review and optimization of your codebase. This entails eliminating any redundant or unnecessary scripts and, where possible, deferring the loading of non-critical scripts.

Optimize Images and Fonts

Image and font optimization is a cornerstone of web performance. Compressing images and utilizing modern image formats can significantly reduce their impact on FID. Additionally, minimizing the use of custom fonts or employing asynchronous loading techniques can yield notable improvements.

Use Asynchronous Loading

Asynchronous loading is a technique that allows non-essential resources to load concurrently with other elements on a webpage. By preventing these resources from blocking the main thread, you can enhance overall interactivity and reduce FID.

Prioritize Critical Content

Ensuring that vital elements of your webpage load promptly is paramount for optimizing FID. By prioritizing critical content, such as text and interactive elements, you can create a more responsive user experience.

Testing and Validation

After implementing the aforementioned strategies, it is crucial to validate the improvements in FID scores. Tools like Google PageSpeed Insights and WebPageTest will serve as reliable benchmarks to measure the effectiveness of your optimizations.

Monitoring FID Over Time

Optimizing FID is not a one-time endeavor; it requires ongoing vigilance. Regularly monitoring FID scores will help you identify any emerging issues and allow for timely adjustments. This proactive approach ensures that your website continues to deliver an exceptional user experience.

Additional Considerations

In addition to the strategies outlined above, there are several advanced techniques that can further enhance FID. Implementing Content Delivery Networks (CDNs), leveraging browser caching, and exploring server-side rendering are all viable options worth considering for comprehensive performance optimization.


Fixing BigCommerce Core Web Vital FID issue in your store is not just an optimization tactic; it’s a commitment to delivering an exceptional user experience. By addressing common causes, leveraging measurement tools, and implementing optimization strategies, you can significantly enhance interactivity and, in turn, drive better results for your online business.


What is the First Input Delay (FID)?

First Input Delay measures the responsiveness of a webpage when a user interacts with it for the first time.

How can I identify FID issues on my BigCommerce store?

You can use tools like Google PageSpeed Insights and WebPageTest to assess your FID scores.

Why is minimizing JavaScript important for improving FID?

Excessive JavaScript can block user interactions, leading to delays in responsiveness.

What role do third-party scripts play in FID issues?

Third-party scripts, such as analytics or social media widgets, can contribute to delays in interactivity.

How often should I monitor FID after making optimizations?

It’s recommended to monitor FID regularly to ensure ongoing performance improvements.

Related Articles

Leave a Reply

Back to top button