I’ll keep it simple: JavaScript is key in today’s environment as it adds interactivity to a page. By doing so, it may alter some key HTML elements that are very important for SEO. You can easily check how a page would look without JS by using this convenient tool by Onley: WWJD.
Realistically speaking, you need only one of the following tools in order to check whether JavaScript might be a problem for your on-page SEO:
- Mobile friendly test
- Rich snippet results
- URL Inspection tool
All the above tools are very useful for any type of troubleshooting as they are showcasing the rendered-DOM resources in real-time (different from what the “view-source” of a page looks like).
Once you’ve run the test, click to see the rendered HTML and try and do the following checks: