Render blocking resources

JavaScript

Scripts can block rendering. To remediate this issue:

• inline critical JS resources in <script> tag
• defer non critical resources with async or defer attributes (see adding interactivity with JS)
• remove unused code

CSS

CSS can also be blocking. To mitigate this:

• split CSS using critical tool
• inline critical (above the fold) CSS in <style> tag
• use media attribute to load only on targeted devices (see render blocking CSS)
• use preload to load non critical CSS asynchronously
• minify CSS

Resources

More information can be found reading this article.