JavaScript errors test

What is it?

Looks for errors reported by JavaScript code when loading every page in the site.

Why it matters

JavaScript powers most interaction within websites. If there are errors in your JavaScript, it can mean:

  • Pages are not working
  • Specific features are not working
  • There may be incompatibilities with the website and certain browsers
  • Code has been deployed with public logging not disabled

Many errors may be benign, but you should use this test to check and be sure.

How to use it

Insites lists any JavaScript errors in a table:

For each error, you will see:

  • Magnifying glass – this opens the Inspector, which shows you a page where the error occurs, together with a stack trace.
  • Ignore – this will learn to ignore this error for every page of the current website. Other websites are unaffected.
  • Type – the severity of the error. You may see Log, Warning, Error and many more here, depending on the JavaScript used.
  • Number of pages – this will show you a list of all of the pages with this error.

Viewing issue in the Inspector will display a full stack trace of the error. You will need an understanding of JavaScript programming to interpret these results.

Clicking on an issue will highlight the part of the HTML page which contains the offending JavaScript, wherever possible. If the part of the page cannot be highlighted, it is because the script which threw the error is not directly called or linked to from the HTML of the page itself. You should review the script file separately.

JavaScript errors that you cannot replicate

Insites loads every page in Chrome, with various modifications to simulate desktop and mobile devices. Bear this in mind when interpreting results: it is possible that certain errors occur which are specific to a given user agent and its capabilities. For example, Insites cannot play sound.

See how Insites sees your websites.