Acting on Feedback: IE9 Release Candidate Available for Download

February 10th, 2011

The Release Candidate of Internet Explorer 9, available now at in 40 languages, reflects our unique approach to building the best experience of the Web on Windows. IE9 also reflects a more open and transparent approach with its regular cadence of platform previews for developers and enthusiasts. With the Release Candidate, we’ve taken to heart over 17,000 pieces of feedback about IE9. You will find the product has made progress on all fronts—performance and standards, user experience, and safety and privacy.

We want to thank the millions of people who have installed and used Internet Explorer 9 during pre-release testing. The value of your feedback in developing the product is hard to overstate. The rest of this post highlights some of the changes made as we listened and acted directly on this feedback.

Performance & Standards: The Web Platform for Developers

The IE9 RC is faster with real world sites. In addition to making the script engine faster, we’ve improved and tuned the rest of the browser as well. You’ll find that Gmail, Office Web Applications, and many other sites are faster as a result of scenario tuning, network cache tuning, and new compiler optimizations. You’ll also find that the RC of IE9 often uses megabytes less memory than the beta because of changes like delayed image decoding. We’ve also improved the performance of things many people do every day, like find on page, and made improvements which extend battery life. In these videos you can see the performance improvements in the RC for text, layout, HTML5 canvas and video, illustrated through new demos on the IE9 test drive site:

IE9 RC supports additional emerging Web standards including CSS3 2D Transforms, HTML5 Geolocation and a set of HTML5 semantic elements. We’ve added support for the HTML5 canvas global­Composite­Operation property and improved the performance of canvas’s Canvas­Pixel­Array. We’ve updated IE9 RC to reflect changes to the DOM events and added accessibility to the HTML5 audio and video controls. These additions reflect our pattern of implementing site ready HTML5 while ensuring developers can experiment with new and emerging specifications through our HTML5 Labs. As these specifications become stable, you can expect we will implement them in IE as we have throughout the development of IE9.

Implementing Web standards is just the start of our commitment to an interoperable Web and Same Markup. Comprehensive test suites developed through the standards bodies are crucial to making sure that browser vendors implement these standards consistently. With this Release Candidate we’ve added over a thousand new test cases for JavaScript and updated over fifty test cases based on community feedback. During IE9 development we have now submitted just under 4000 test cases in total for standards like HTML5. We have submitted these tests to the appropriate standards bodies for feedback and eventual inclusion in their official test suites. You can try them out for yourself at the IE Test Center.

Web Standard Number of Submitted Tests Internet Explorer 9 RC Mozilla Firefox 3.6.13 Opera 11.01 Apple Safari 5.0.3 Google Chrome 9.0.597.84 Internet Explorer 8
HTML5 111 99% 50% 61% 60% 77% 0%
SVG 1.1 2nd edition 70 100% 76% 94% 84% 89% 0%
CSS3 134 100% 59% 76% 71% 75% 10%
DOM 127 100% 93% 82% 84% 89% 6%
Navigation Timing 10 100% 0% 0% 0% 0% 0%
Web Applications 77 100% 49% 40% 35% 36% 0%
JavaScript 3413 100% 47% 47% 86% 89% 6%

User Experience: Site-Centric Browsing, Improved

With the RC, we’ve acted on thousands of pieces of feedback about how to improve IE9’s clean, site-centric design. Our IE9 beta telemetry data shows that 97% of sessions had 5 or fewer tabs open. At the same time, we care deeply about the other 3%. Many of you weren’t shy about sharing your ideas for how the browser could accommodate more tabs. We listened and we took your suggestions to heart. With the RC, you can put tabs on their own row taking advantage of the maximum available space for all your tabs:

Why is this change so important? You said so:

Based on your feedback, we also made it much easier to refine search queries in the One Box. Based on your feedback, IE9’s download manager will now display the download speed, and download notifications are animated and more noticeable. Based on your feedback, pinned sites now support multiple home pages – “redefining awesome” according to this comment. With Paste & Navigate (Control-Shift-L), hardcore enthusiasts can save a step pasting into the address bar. We’ve reduced the number of pixels in the frame, and updated the visuals, making the active tab easier to identify, and made it easier to close inactive tabs. We acted on your feedback unless there was a clear pattern of inconsistency (for example, big back button is bad… no, it’s good). There’s a list at the end of this post of additional improvements, and we will detail them in future blog posts.

In hindsight, this comment from the original beta post was prescient:

  • Tabs on same line as address bar! If this is believed to be the better way of doing things by yourselves then fine, leave it as defaullt but at least give us the option to move it around!!
  • Download speed not shown in download dialog. ??? Not acceptable.
  • Somebody said something about paste and go…it is indeed a useful feature. Can’t be too hard to implement 😉

In this video you can see some of these changes that resulted from the feedback you provided:

In short, developers and enthusiasts gave us some great feedback on how we can make our site-centric design even better. We listened, we acted, and we want to thank you for your contribution.

Safety and Privacy: Trustworthy Browsing

On today’s Web, consumers are increasingly wary, often out of necessity. They face security risks like malicious sites and phishing scams. Even on sites consumers know and trust, bad things often happen. It’s easy to almost follow a bad link from a friend on Facebook, or become a victim of malvertising when a malicious advertisement appears on an otherwise trustworthy site.

Based on your feedback, we’ve made it easy to “turn off ActiveX” for all sites and then re-enable it, site by site, as you see fit. You can try IE9’s ActiveX Filter at the IETestDrive site here.

IE9 now includes Tracking Protection because consumers have become increasingly concerned about privacy. IE9 enables consumers to express their preference for privacy, and also gives consumers a mechanism to enforce specific aspects of that preference. Consumers can do this by choosing Tracking Protection Lists from organizations they trust. These lists can block and allow third-party content in order to control what information consumers share with sites as they browse the Web. By controlling the flow of information to sites, these Tracking Protection Lists help users protect their privacy. Unlike other solutions, IE9’s benefits users even if Web sites do not respect the user’s preference to not be tracked. The ability for a site to determine that the user has expressed a desire to not be tracked (by turning the feature on) is inherent in the design of Tracking Protection.

Today the first set of Tracking Protection Lists created by trusted organizations are now available on the Web. Adding a tracking protection list in the IE9 RC is as simple as clicking a link on a Web page. At this early stage we have linked to these Tracking Protection lists on the IE Test Drive site so consumers can find and try them and immediately enjoy a level of choice and control with respect to their online privacy that didn’t exist before today.

What’s Ahead

The Web is beautiful and powerful because of the developers and designers who build it. Enabling them to build rich and immersive sites that feel like native applications on your Windows 7 PC is at the heart of our approach with IE9. Here’s a video of how several influential members of this important community are talking about IE9:

The development process of IE9 has focused on building the best experience of the Web on Windows. Our approach to building a faster Web-browsing platform involves harnessing more of the PC’s hardware for Web pages. Our approach to Web standards and interoperability involves real-world developer scenarios and modern software engineering practices like comprehensive test suites. Our approach to designing a clean, site-centric Web browsing experience involves using everything available around the browser that people use regularly, so people can now pin sites to the Windows taskbar and Web sites can program taskbar jump lists. Our approach to building a safer, more trustworthy browser involves effective consumer protections from real-world risks, like programs they download or sites that might unexpectedly track them. All of these things taken together has resulted in the fastest adopted beta in IE history, with over 25 million downloads to date.

Over the next few weeks, we will continue to listen closely and carefully to feedback from the worldwide community about the Release Candidate. We appreciate the work that developers and IT professionals will do to test their sites and prepare for the final release that will come shortly. We will automatically update IE9 beta users to the IE9 RC. After the final release, we will automatically update IE9 RC users to the final build.

On behalf of the individuals and companies who have worked so hard with us to deliver this Release Candidate, and the many people at Microsoft who have built it, thank you for visiting and trying IE9.

—Dean Hachamovitch, Corporate Vice President, Internet Explorer

P.S. Here’s the cheat sheet from the IE engineering team hallway for what’s new in the RC:

Additions to IE9 between Beta and RC
Performance Standards & Platform User Experience Trustworthy Browsing

Elapsed Time

  • Significant scenario tuning
  • Chakra performance optimizations
  • Network cache improvements (size, priorities, etc.)
  • Compiler optimizations and binary training

Large Working Set Reductions

  • Delayed image decoding (1-50MB depending on site)
  • Reduce memory footprint of InPrivate Filtering heuristic generation (5MB)
  • Binary size reductions (over 1MB saved)

Other Real-World

  • Decrease timer resolutions to 4ms from system default of 15.6ms
  • Timer resolution aware of Power Options
  • Find on Page performance


  • CSS3 2D Transforms


  • DOM events (updated for spec changes)


  • Canvas global­Composite­Operation
  • Canvas­Pixel­Array performance
  • Geolocation API
  • HTML5 semantic elements
  • Allow alternative video codec (WebM)
  • Accessibility of media controls

Compatibility View List

  • Software fallback list for GPU/drivers in XML CV list
  • F12 console logs for CV sites and support for Tracking Protection


  • Optional full tab row
  • Close box for inactive tabs
  • More identifiable active tab


  • Paste & navigate (Ctrl+Shift+L)
  • Refine search queries in onebox
  • Reduced frame pixels
  • Better favorites bar integration
  • Menu bar toggle
  • Intranet search by default option


  • Display download speed
  • Auto dismiss notifications
  • Animated downloads notifications
  • Improved app reputation notifications

Pinned Sites

  • Pin to vertical task bar
  • Multiple home pages in pinned site
  • In-page drag-to-pin support

Tracking Protection

ActiveX Filtering


  • InPrivate pinned sites

February 10, 2010, 12:00 PM: Test Center Results and Additions to IE9 between Beta and RC tables converted from images to HTML tables.