IE9 Beta - How Accurate is IE7 / IE8 Emulation?

I’ve been playing with the IE9 beta. I notice that if I hit F12, I get a “developer tools” control panel. Among other things, it contains a “browser mode” setting and a “document mode” setting. These can be set from IE7 through IE9. Going to supportdetails.com when the IE9 beta is set to IE7 or IE8 reports the corresponding browser version. But I’m sure it’s just reading that from the HTTP headers. My question is how accurate are the IE7 and IE8 emulations within IE9? Since installing the IE9 beta seems to have wiped out my version of IE8, I’m concerned about testing web sites I’m working on for people using IE8. Does the IE9 emulation code truly render a web site exactly as the “real” IE7 and IE8 would? Are there any ways I can check / confirm this?

Thanks!

Well, they suck automatically for testing scripting behaviors and there are still some incorrect handling of bugs – it’s the same with IE8’s alleged IE7 mode.

It’s why I don’t use any of those and instead have multiple native installs set up in Sun VirtualBox. Old valid XP and Win2k keys are a dime a dozen (surely you can find a dead laptop or three somewhere) and you are most always better served by testing in the real deal.

I’ve tried using IETester, and I’ve tried IE8’s compat mode, and they both fall a hair short of the real thing… it just bit me in the backside a wee bit too often. I don’t expect IE9’s behavior to be any different – which is why I’ve not even tried it’s compatibility modes.

Using VM’s also lets me play with font metrics (large fonts/120dpi vs. small fonts/96dpi) without messing up my host OS or constantly rebooting.

I actually had or have the same question. It indeed whiped out IE8 that’s why I keep using my IE tester where IE 8 is included’

IE Tester