Compat Inspector

Compat Inspector is a JavaScript-based testing tool that analyzes your site while it runs. Compat Inspector watches for patterns of interaction known to cause issues and reports them automatically. This allows you to identify problems quickly without first memorizing a bunch of documentation. See this page to learn how to use it.

Live Example: Fixing Tooltips

To help demonstrate Compat Inspector, known compatibility patterns have been introduced into the tooltip script used for this page. Use Compat Inspector to learn about the issues present in the tooltips above. Just click on the Compat Inspector widget in the upper right-hand corner of the page to get started.

For a given reported issue, check the "Verify" checkbox and refresh the page to temporarily simulate the expected behavior. Focus on one issue at a time. Although you can "Verify" multiple issues at once, typically only one represents the root cause of the problem. Continue this process until the tooltips start working correctly. After that, take a look at the patched version of the tooltip script.

Running Compat Inspector on Your Site

Add the following script before all other scripts on each page you want to test:

<script src=""></script>