Throughout IE9, we have written about how
developers expect browsers to be compatible with the sites they use
every day. This blog post covers a few ways we measure and ensure compatibility
with the Web and how
your feedback made a
Measuring compatibility with the Web
We measure Web compatibility through many different mechanisms. These include:
Customer feedback: Most important, we listen and act on feedback from the
community. With 33 million downloads of IE9 Beta and RC, users logged over
23,000 bugs. That’s over six times the amount of feedback we received in
previous versions (Users logged more bugs for IE9 in part because we made it easier
opening the Connect program to everyone).
Professional testing: We test thousands of high traffic sites on a regular
basis. These sites are popular with users and important to daily life around the
Telemetry: Across hundreds of billions of browsing sessions, we gather telemetry
data when users click the Compat View button. We use this data to determine what
additional sites to test and add to the
Compatibility View (CV) List.
We use all of this data, analysis, and testing to improve IE9’s compatibility with
the Web. We also use it to determine what sites are added and removed from the CV
List. For example, thanks to your feedback, we removed hundreds of sites that have
updated since Beta such as bankofamerica.com
and washingtonpost.com. This helps ensure
that all users have the best browsing experience with these sites.
New for the IE9 Compatibility View List
We made three improvements to the IE9 CV List between Beta and the final release:
The IE9 CV List includes the
software fallback list for GPU/drivers, which you can find at the end of
the CV List xml file.
This means we can update the CV List to provide users with a better browsing experience
within days of discovering GPUs or drivers that are incompatible with IE9.
The IE9 CV List includes subdomain support. This enables IE to run a specific subdomain
in a compatible document mode, while keeping the rest of the domain running in the
latest Standards mode.
F12 Developer Tools tells site developers when sites are on the
IE9 CV List, their
local CV List, or a
Group Policy-configured CV List, as shown in the screen shot
Ensure the best experience for your site
In closing, please continue to
verify your site works well with IE9. Start by sending IE9 the
same standards-based markup and script you send other browsers, and
feature detection, not browser detection. Check to make sure your site is
not on the CV List.
If it is, that means customers have reported incompatibilities with your site and
IE9. To be removed from the CV List, test your site with the CV List off (Press
“F12” to bring up F12 Developer Tools and select “IE9” from the Browser Mode menu),
update your site to be compatible with IE9. When you have verified that
your site works in IE9 Browser mode, email email@example.com
with the information at the
bottom of this Web page and ask for your site to be removed from the IE9
—Marc Silbey, Program Manager, Internet Explorer