Manage and minimise the impact of third-party code

Reducing the impact of third-party code is crucial for optimising the performance of your website. Third-party scripts, such as ads, analytics, widgets and social media buttons can significantly slow down your site by consuming resources, increasing load times and causing rendering delays. In this article, we explore several strategies to effectively manage and minimise the impact of third-party code:

1. Audit and Evaluate

   – Identify third-party scripts: Use tools like Google Lighthouse, WebPageTest, or Chrome DevTools to identify all third-party resources loaded on your site and their impact on performance. Determining their performance impact on your website is the first step toward optimising them.

   – Evaluate necessity and ROI: Assess whether each third-party script is essential and consider the trade-offs between functionality and performance. Remove or replace scripts that are not delivering sufficient value. You can also utilise content delivery networks for faster delivery, version and cache scripts for efficient browser caching,

 

2. Lazy Load Non-Essential Scripts

   – Defer loading: For scripts that are not critical to the initial page load, such as social sharing buttons or comment sections, use lazy loading techniques. This means loading them only when they are needed. For example, when they enter the viewport or when a user interacts with the page.

 

3. Host Third-Party Resources Locally

   – Reduce DNS lookups: By hosting third-party scripts locally, you can reduce DNS lookups and have more control over the caching of these files. However, this approach requires keeping the scripts updated manually and can sometimes violate terms of service, so it should be done with caution.

 

4. Limit Third-Party Impact

   – Use iframes: For embedding widgets like videos or social media posts, consider using iframes. This isolates third-party code and prevents it from blocking the main thread.

   – Set timeouts: Implement a timeout for third-party scripts. If a script takes too long to load, abort loading it to maintain the site’s performance.

 

5. Asynchronous Loading

   – Async attribute: Use the `async` attribute in script tags. This allows the script to be downloaded in parallel to the page parsing and will not block the DOM and CSSOM construction.

   – Non-render blocking: Ensure that third-party scripts do not block rendering by placing them at the end of the body tag or using defer and async attributes effectively.

 

6. Monitor and Optimise Performance

   – Performance budget: Set a performance budget for third-party scripts and stick to it. This helps keep their impact in check and prioritises overall site performance.

   – Regular audits: Continuously monitor the performance impact of third-party scripts and re-evaluate their necessity. Technology and site priorities change, so regular checks are crucial.

 

7. Use Content Security Policies (CSP)

   – Restrict origins: Implement Content Security Policies to control the sources from which scripts can load. This not only improves your website’s security but also prevents unauthorised third-party scripts from slowing down your website.

 

In Summary…

By implementing these strategies, you can mitigate the performance issues caused by third-party scripts while still leveraging their functionality. This balance is key to maintaining a fast, responsive, and engaging user experience. 

For more tips on how to improve your website performance, with third party code and beyond, contact us today.