Detecting IE by looking for "Trident" string

Question

In my web-app I am using a transparent blur filter to overlay on top of a video. This is doable with all browsers except IE10/11. Since the blur filter is a CSS property, I can't really do proper feature detection, as I should be doing. Instead, I am using this:

if(navigator.userAgent.indexOf("Trident")>-1) { // IE ... }

If IE is detected, I use a different filter (non-blur) that works there.

Is there any situation in which this code might give a false positive? Are there any blur-compatible browsers that use the Trident engine?

Edit: I know IE8 and IE9 have their own blur filters, but for consistency's sake, we decided to use the same alternative filter for all versions of IE.

Answer 1

This page explains the user agent strings used by Internet explorer:

http://msdn.microsoft.com/library/ms537503.aspx

It says that the Trident token was only introduced in IE8, so you might want to check for "MSIE" instead or as well.

There is also this page:

http://msdn.microsoft.com/en-US/library/ms537509.aspx

which is "archived and is no longer actively maintained" but does include a lot of useful information on detecting Internet Explorer.

Answer 2

You can detect filter support, as described in the answer to this question: How can I feature-detect CSS filters?