Check if user is using IE with compatibility mode

Question

I am looking for some code (either PHP or JavaScript) would work well to check if a user viewing a page is using compatibility mode. Then I can use that code to do some conditional statements, or basically give them a notification to turn it off.

Accepted Answer

Force them to:

```
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
```

This will disable Compatibility View, unless the user then goes and specifically turns it off by going into the Developer Tools and changing it.

Check if user is using IE with compatibility mode

Solution

Problem