Will adding the script slow down my website?
No, adding the SEOJuice script is designed to have a minimal impact on your website’s performance. I use the script on my website as well, here's what google pagespeed is saying:
As you can see "main-thread blocking time: 0ms", so the script is practically invisible.
How SEOJuice Ensures Speed
Lightweight Script: The SEOJuice script is highly optimized and lightweight. It adds only a few kilobytes to your site, which is negligible compared to most modern websites.
Deferred Loading: The script uses deferred loading, meaning it loads after your main content. This ensures it doesn’t block critical rendering paths or delay the display of your page’s primary content.
CDN Delivery: The script is served via a fast, globally distributed Content Delivery Network (CDN). This minimizes latency and ensures quick load times regardless of the visitor’s location.
Small Processing Requirements: SEOJuice focuses only on tasks like internal linking, on-page optimizations and accessibility, which are lightweight operations with your HTML. (Also I've optimized the script heavily to make sure it's fast)