Internet Explorer 9


Skip navigation.

Site search

Site navigation

Internet Explorer 9

It is important to note that even though Microsoft will continue to support Windows XP until 2014, Internet Explorer 9 is not available for Windows XP, and is only available for Windows Vista and later. Users of earlier operating systems will either be stuck with Internet Explorer 8 (or earlier), or can switch to alternative browsers which continue to be supported.

Summary of the changes

The Internet Explorer 9 is available, and for once it seems that an attempt has been made to make a jump in standards support. It is still behind most other browsers (that's nothing new), but many popular standards have now been implemented, allowing pages to be written with less reliance on code branching for IE's non-standard APIs. Several CSS 3 advances have been made, and several missing DOM 2 and 3 modules have finally been implemented according to the standards, in addition to the existing non-standard versions. A few new items from HTML 5 have also been added, along with basic support for SVG.

As always, most of these enhancements are only available in standards rendering mode. While this may partially make sense for CSS features, it is problematic for JavaScript features. Generic scripts that are designed to work on any page (from simple scripts to downloadable libraries such as jQuery) cannot rely on any of the new features, even if they do not need to cater for IE 8-, because on a quirks mode page IE 9+ will intentionally drop support for those features. In addition, if the user enables compatibility view on any Web site (this is enabled by default on all intranet sites), IE 9 reverts to IE 7 rendering for that site, and once again drops support for all of the new enhancements. Generic scripts may also be used on a number of intranet sites, and will need to cope with this as well.

The main changes are as follows:

There are still some frustrating oversights, of course, and lingering signs of rushed implementations that have failed to cover useful cases:

You may notice that most of the additions are things that are tested by Acid 3 - while it is nice to know that Acid 3 can have that influence, it would also be nice for the other important things that were not tested in Acid 3 to get some attention. It would also be nice not to have to produce high profile tests like Acid 3 just to encourage the dominant browser's vendor to start implementing standards which they themselves contributed to (most of the DOM 2 modules were ready for implementations 12 years ago) - oh well. Its score on Acid 3 is currently the lowest of all major browsers, but far higher than it was in IE 8. At the time of release, the score was higher than that of Firefox's public 3.6 release, but slightly lower than Firefox 4 beta. Opera and Safari (and therefore other WebKit browsers like Chrome) passed the standards parts of the test a number of years beforehand.

Running IE 9 and IE 8 or IE 7 on the same computer

The IE 9 install overwrites the IE 7 or IE 8 install. It is possible to use IETester to test previous versions. IE 9 has the menu item and button "Compatibility view" to switch it into IE 7 mode, which is close to a real IE 7 install, but not perfect. A few of the IE 9 script properties still exist, and a few little CSS differences are present. Still, it is not a bad approximation. For now, this is the best approach. It does not seem to be possible to run IE 8 on computers where IE 9 is installed. For testing in IE 8, open the developer tools (F12), and use the menu to set the browser mode to IE 8 (or 7). Like the IE 7 compatibility mode, this will not be perfect, as certain new methods, properties, and CSS values may still exist.

This site was created by Mark "Tarquin" Wilton-Jones.
Don't click this link unless you want to be banned from our site.