The Time-to-Interactive metric measures how long it takes for the web page to become “interactive”.  As is recommended by Google, to improve this score, you should defer or remove unnecessary JavaScript work that occurs during page load.

If the optimized time-to-interactive is considered slow, then you can try to

  • Disable any unnecessary plugins which may be be adding JavaScript to your pages.  Once disabling any unnecessary plugins, you will need to clear your optimized pages cache and then re-request a PageSpeed scan.
  • Determine if there are any JavaScript resources that are not necessary for the initial page load, add those file names to the Settings > Lazy Loading > Lazy Load Scripts panel.  Any .js file that you add in this panel will not be loaded and executed in the page until the user has begun to scroll down through the page.