Third-party scripts are code files that load from external servers — not your own website. They include analytics tags, ad pixels, live chat tools, social media buttons, A/B testing tools, and customer feedback widgets.  Every third-party script adds an HTTP request to a server your website does not control. If that external server is slow, overloaded, or temporarily down, your page waits.

The result:

slower load times, frustrated users, and lower conversion rates.  Research shows that a one-second delay in page load can reduce conversions by up to 7%. Google also uses page speed as a ranking factor — so slow scripts hurt your SEO too. 

How to fix it:

Use Google PageSpeed Insights or WebPageTest to identify which third-party scripts cause the biggest delay. Remove scripts you no longer actively use. Load non-critical scripts asynchronously or after the page has finished rendering. Self-host fonts and libraries where possible.  The most effective fix is server-side tagging — it consolidates your tracking scripts on a server, so the browser only needs to make one lightweight call instead of dozens of separate requests. 

Seers.ai’s server-side tagging reduces the number of external requests your browser makes, directly improving page speed and Core Web Vitals.