Compatibility View List and IE8 RTW

I’ve blogged about the Compatibility View features included in Internet Explorer 8 a few times during the Beta 2 and Release Candidate milestones. Now that Internet Explorer 8 has released, I wanted to follow-up with a quick post highlighting the content that’s been created on MSDN regarding the Compatibility View List.

To review, Internet Explorer 8 includes a suite of features under the umbrella term ‘Compatibility View’. These features give users a way to mitigate website compatibility problems they may encounter while browsing the web – compatibility issues often caused by Internet Explorer 8’s better implementation of web standards. By default, Internet Explorer 8 displays content in its most standards compliant way and this can cause compatibility problems on websites that still expect the older, less interoperable behavior from IE. Users can override IE’s default behavior by choosing to view a site in Compatibility View - there’s an icon that appears next to the ‘Stop’ and ‘Refresh’ buttons in the address bar that controls this. Overall options for the feature set can be found in the Tools menu.

During the development of Internet Explorer 8, the IE team analyzed Compatibility View button usage telemetry data, paying close attention to the type of compatibility experiences our Beta users were having on high traffic websites. We combined that telemetry data with other feedback sources – customer-filed bugs, Report a Webpage Problem data, our own compatibility testing, etc… - to create a list of high traffic sites that are likely best displayed in Compatibility View. During the first run experience, we offer users the choice to use this Compatibility View List as part of their everyday browsing experience. Visiting websites on the list causes Internet Explorer 8 to display the site in Compatibility View rather than IE8’s default “best standards mode”. In other words, it’s as if the user pressed the Compatibility View button for all sites on the list with the benefit that the end user avoids having to first experience a website compatibility failure to make the determination that these particular sites are best viewed in a non-default manner. You can view the list currently available on your IE installation by typing ‘res://iecompat.dll/iecompatdata.xml’ into the browser’s address bar. Note that the list is only active if the ‘Include updated website lists from Microsoft’ check-box at Tools --> Compatibility View Settings is selected.

Coinciding with the release of Internet Explorer 8, we’ve created a content store on MSDN that discusses the finer-grain details of the Compatibility View List. There you can find answers to common questions –

  • What process did the Internet Explorer team follow to create the list?
  • Is my site / domain on the list?
  • How do I remove my site / domain from the list?

We’ve also created a tracking spreadsheet that provides a living history of sites on the list – domain name, when the site was added, and the current status. The Compatibility View List is updated on a regular cadence (in a period mirroring IE security updates, approximately every 2 months) and the status field helps site owners determine whether the currently shipping version has satisfied the removal request or whether the removal request will happen in an upcoming version of the list.

In closing, we on the IE team greatly appreciate all of the feedback you’ve provided regarding Compatibility View. That feedback has helped us create a feature set that meets two important goals of the release, goals that are often at odds: improved interoperability through a better implementation of web standards *and* providing a great user experience on existing websites. Please keep the feedback coming.

Scott Dickens
Program Manager

Comments (41)
  1. Venkat says:

    Thanks to IE team! You made me discover the web all over again. IE8 actaully made me do something that I didn’t do for so long – making FireFox my primary browser! IE8 practically broke 8/10 sites that I visit on a day to day basis. I got frustrated within 3 days of downloading and installing IE8. My trust for FireFox has gone up by 3X after I started to use IE8.

    Bye Bye IE!

  2. Dan says:

    Venkat, why not try posting something useful?  Trolls only get credit if they actually provide incriminating details.  

  3. Brett Merkey says:

    I have the required settings as indicated, but entering the "res" address returned only:

    <?xml version="1.0" encoding="utf-8" ?>

     <ie8compatlistdescription xmlns="; />

  4. hAl says:


    Name those 8 sites that are broken (an you vist every day)

  5. Maz says:


    I’m pretty sure venkat just made up that statistic and has never even bothered to try IE8, and is just another Firefox fanboy spamming his ridiculous Firefox cult to everybody.

  6. hAl says:


    You are probably right

  7. steppres says:

    I’ve used IE8 for the past 3+ months and have only come across a few broken sites when using the default standards mode (one was Gmail, but thankfully that was fixed for the final version of IE8). I think most users won’t encounter many/any broken sites especially if they are using the update list.

  8. steppres says:


    Firefox, not FireFox. Geez…

  9. The Hater says:

    I really hope you guys realize how much I love this feature. We get a list of all of the sites still relying on ugly hacks so much that they couldn’t pull their heads out long enough to get things working (or at least deferred within their control).

    The public shaming, it warms my heart…

  10. mocax says:

    does the list in the xml file include sites that i added manually?

    and will my list be sent to microsoft secretly?

  11. EricLaw [MSFT] says:

    @mocax: No, the XML file will only show the Microsoft-generated sites list; your choices are maintained elsewhere.  

    No, your list is not sent to Microsoft. Our privacy statement is here:  

    You’ll note that if you’ve opted into real-time SmartScreen Filtering reputation checks, then URLs sent to Microsoft will indicate whether or not you’ve chosen to view the site in Compatibility View.  This information is only reported in the course of normal operation; we never upload the complete list or anything like that.

  12. Glen Fingerholz says:

    @The Hater

    Keep on hating, don’t care 🙂

    Some businesses have more urgent things to do than update their site to use standards mode IE 8. It works with compat. view, therefore it works in IE, therefore it doesn’t get a high priority!

    It works in Firefox, it works good enough Safari/Chrome, it works in IE (compat. mode).

  13. PatriotB says:

    @Brett Merkey — looks like the initial list that shipped with IE8 is blank; you should have a Windows update waiting for you that has the actual list.

  14. Mitch 74 says:

    Personally, I resent the ‘FireFox fanboi’ remark. As said, it’s one capital ‘F’ (a firefox is a small red panda that looks somewhat like a fox; look it up).

    Next, if not for Mozilla Firefox we’d probably not have a CSS 2.1 compliant IE 8 with actually very good developer tools built-in right now.

    Last, if the IE team starts developing IE for non-Windows platforms again (IE4 had a UNIX version, Macs had IE 5.2), I may use IE.

    But since IE 8 is Windows only, fat chance I’ll do that outside a virtual machine.

  15. cough cough says:

    Just in case you forgot, the rest of the software development world calls it RTM.

  16. toby says:

    Ok so I’m ok with the whole compatibility view thing but I have to ask.

    What is going to happen when IE9 comes out? Are you going to have 2 compatibility buttons? 1 for IE7 behavior and 1 for IE8 behavior?

    I personally hope that IE8 is "End-Of-Life" for IE7 compatibility and that in IE9 it is no longer there.  If developers are warned NOW, in advance, they will only have themselves to blame if they are not ready in 2012.

    However if MSFT waits on this they will be stuck in a pickle when it is time to beta/rc IE9.

  17. Will Peavy says:

    @cough cough:

    RTM = Release to Manufacturing

    RTW = Release to Web

    The two are similar, but not the same.

  18. steve_web says:


    Please for the love of god, someone on the IE Team get in touch with the Connect team and tell them to get rid of that @#$%@ing flyover!!!!!

    That is by far the MOST UNBELIEVABLY UN-USABLE PIECE OF JS/HTML widgetry I have ever seen!

    It is beyond frustrating.  I just want to click on a link but I CAN’T!!!!!! because the silly popup takes focus (not to mention is slow to load)

    I realize this isn’t under direct control from the IE Team, but the Connect Team REFUSES to listen to outside sources on ANY usability issues with "their" system.


  19. Richard Fink says:

    Is it true that IE9 is going to have an "Idiot Filter" that weeds out malicious, unproductive blog posts automatically?

    Productivity will soar worldwide!

  20. Maz says:


    One can only hope…

  21. SamYeager says:

    I must agree with steve_web about the popup when trying to select entries on Connect. I realise that some people may well find it useful :shrugs: but why not give the rest of us a, saveable, option to disable it.

  22. Kit says:

    Just a note, the language used for Hong Kong on the download page is wrong, that’s simplified Chinese not Traditional Chinese hope you guys change that as soon as possible. Thanks.

  23. Mitch 74 says:

    About the RTM/RTW discrepancy: it would seem illogical to "Release [IE] To Manufacturing" since IE is currently only released over the Intarwebz; IE may reach "RTM" only when it is released on a CD/DVD (which is actually manufactured), and that may happen only if:

    – as before (like in 2000 or XP versions), MS Office forces the installation of an IE version; since Office dropped Trident in favor of a built-in HTML engine, even that is unlikely;

    – Windows 7 reaches RTM (IE 8 included);

    Now, of course, we could get a policy reversal from MS: next Service Packs for all supported OSes (XP SP4, 2k3 SP3, Vista SP3) include IE 8 – and the ability to remove IE (as in Win7) before 7 is actually out.

    Don’t bet on any it. So for now, IE 8 is "Release(d) To Web" – meaning that its code is frozen, its (apart from securiy) bugs are set in stone and only a cataclysmic oversight (as in, popup blocker added to IE 6 in XP SP2 to prevent popup storms) may see a change in it.

    @MSFT crew: was it voluntary to keep the "100% CPU use and sometimes crash" bug on ‘unknown’ container boxes containing off-rendering area variable size boxes in IE8 Compatibility mode? What use does it serve to reproduce CPU hogging and crashes?

  24. Mitch 74 says:

    above post: ‘unknown’ is in fact ‘unknown size’.

    To make the bug more explicit: imagine a DIV with a set dimension (say, display:block; position: fixed; top: 5px, bottom: 5px, left:5px; right: 5px) and a scroll bar (overflow:scroll). Said DIV contains another element that may change size on hover (say, a DIV that has hidden content revealed by a mouseover).

    You’ll then see the parent’s DIV scrollbar become a bit crazy, and CPU use skyrocket (sometimes leading to an IE crash, and even once in my numerous tests, a BSOD – no kidding). That happened first in IE 7 beta 2, and is still here in IE 8 RTW in Compatibility mode (but not in Edge mode, thankfully).

    I really wonder about this bug, and why it hasn’t been fixed (I reported it on this blog in 2006).

    Note: I haven’t been able to reproduce this bug in IE 6 (even with its limited :hover support), and a quick workaround is to give the child DIV (or whatever your variable size container block is) a bogus min-height.

  25. Dan says:

    Mitch, the ie team has previously said that they use RTM/RTW interchangeably.  If for some reason you think this is worthy of protest and extensive discussion, start a up a blog and move your inane conversation over there.

    Your crashing bug sounds interesting, although it sounds like hardware error to me.  On NT-based OS’s you need a driver bug or hardware error to BSOD.  How about you post the URL of a test case?

  26. ieblog says:

    @Kit: Please provide the exact URL of the page where you saw this?

    We see that the XP Hong Kong link on the worldwide sites page (香港特别行政区 – 中文 繁體)

    Points to Traditional and that serves up CHT bits.


  27. SaveIE6 says:

    I am sick of hearing about IE7/IE8/IE9. I want to keep using my IE6 because it has allowed me to use the web unlike IE7 and IE8 with their memory hogging attitudes. Please think about rolling back to developing IE6.

  28. William Pennington, Sr. says:

    I entirely agree, SaveIE6. They need to get AOL back on track with IE 6 before AOL buys Mozilla. With their huge and expanding membership pool, it would be a death knell for the internet that we know and love. Microsoft needs to stop wasting their time making up bogus standards like CSS and ECMAScript, and get back to the de-facto basics (e.g. re-writing IE 6 in PHP). They also need to start porting IE 6 to platforms that really matter (e.g. OS/2), to prevent any further losses.

    They also need to get a spokesman to sell people on IE 6 again, and hiring a well-respected, insightful journalist like John Dvorak would go a long way.

    P.S.: You guys need to sell IE 6 on the iPhone. A lot of people refuse to buy one because it’s missing IE 6.

  29. Maz says:


    Nice April fools joke.

  30. こんにちは、五寳です。 互換表示について、IEBlog : Compatibility View List and IE8 RTW や MSDN : Understanding Compatibility

  31. WebDesign IE says:

    Hello everyone, I must admit that after a short while with IE 8 I switched back to Firefox. Microsoft made web designing more difficult. By now it was enough to make some fixes for Ie6 and separate css style for IE7. But now you need to have 3 different versions of IE in mind when writing XHTML code. Fortunately Firefox and Safari can render CSS 2.1 perfectly.

  32. zzz says:

    In IE8 this page isn’t shown in compat mode. But try select + copying the "svn checkout …" part of the page. It doesn’t allow doing text selection inside that box. In compat mode it works.

  33. Using IE8? Issues ? Something broken? Truth is, on Vista I stopped using IE8 in the middle of the beta

  34. Dan Kegel says:

    At first glance this list looks like a

    real effort to help nudge sites towards

    web standards.  There may be some false

    positives on it (any big list is going to

    be noisy), but on the whole I love the idea.

    And I’m a die-hard Linux user.

  35. IEBlog says:

    With the “final” release of IE8 for Windows Vista and other versions of Windows in several languages

  36. IEBlog says:

    As we described on Monday , the IE8 in Windows 7 RC includes additional tab “hang” reporting functionality.

  37. Доступно обновление для IE8 в Windows 7 RC Как было написано в предыдущем сообщении блога , IE8 в Windows

  38. IE8 on Windows 7 RC: Boink Boink

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