The modes were intended to help companies continue to use legacy web applications while developers made fixes.
However, far more of us used browser modes to test old IE rendering. We certainly shouldn’t since the modes are an unreliable imitation of the real browsers. For example, you can find features such as CSS3 animations working in IE10 when it’s switched into IE9 mode.
Many developers applauded Microsoft’s decision. I did. Browser modes are flawed, impart a false sense of security and have become increasingly unnecessary as IE improves.
Many developers disagreed…
Browser modes allow devs to quickly reproduce something a user is experiencing, and provides a quick way to test fixes in your own environment, yes the final fix should be tested in a non-emulated browser, but MS makes that hard since you cannot have more that one version of IE on a system at a time.Despite browser modes being a poor substitute for oldIEs, many find them convenient for quick and dirty testing. Starting up a virtual machine may only take a few seconds on a fast PC, but browser modes are almost instantaneous.
Anyway, they’re back. Microsoft has listened to the complaints and re-implemented browser modes in IE11 on Windows 8.1 (technically, they were always lurking beneath the surface and just hidden). I’m not aware of any official announcement — I found them by accident when tinkering with IE11 final on Windows 8.1 for a SitePoint review.
To access the modes, start the F12 Developer Tools, click the Emulation icon at the bottom, and choose a Document Mode — they’re not named “browser modes” any longer.
Has Microsoft made the right decision? Ironically, the lack of browser mode functionality would have dissuaded some companies from upgrading IE9/10. Fewer upgrades means longer having to support oldIEs. I suspect they’ve done the right thing.
That said, please don’t use browser modes! I know they’re convenient, but they could cause more problems than they’re worth when real IE8 users report issues with your site or application.
Are you pleased to see the return of IE browser modes?
Source: http://www.sitepoint.com/ie11-browser-modes-return/
