The Platform Preview is an early look at the Internet Explorer platform so some features are incomplete, some may change, and some may be added. To learn more about this preview of the Web Platform, please see the Internet Explorer 10 Developer Guide. These release notes list new features available in the latest Platform Preview and known issues with those features. To report issues, and provide feedback please click on Report Issue and click Send Feedback.
Internet Explorer 10 Platform Preview 4 is the fourth public preview of the IE10 web platform. This preview release includes support for major platform features like Cross Origin Resource Sharing (CORS), improvements to the Web Worker developer experience, File API, top level Quirks mode emulation and more.
The Internet Explorer Platform Preview requires the Windows 8 Developer Preview (x86 or x64) Operating System. To download the Windows 8 Developer Preview, please follow the instructions here
The Platform Preview ships with a pre-defined compatibility view list that is designed to mitigate website compatibility problems you may encounter while using the Platform Preview. Although Internet Explorer constantly updates its compatibility view list, the list consumed by the Platform Preview is static. To use the most up-to-date version of the compatibility view list with the Platform Preview, please follow these steps:
The platform preview will pick up the new CV list once you restart the application.
No VML in IE10 Standards and Quirks Modes
The Internet Explorer-proprietary Vector Markup Language (VML) is no longer available in IE10’s standards and quirks modes. Web developers are advised to use standards-based Scalable Vector Graphics (SVG) instead. VML is still available in IE10 in legacy modes 5, 7, 8, and 9 though the performance of VML in those modes is inferior to SVG.
No Legacy DX Filters in IE10 Standards and Quirks Modes
Internet Explorer-proprietary DirectX-based visual filters and transitions are no longer available in IE10’s standards and quirks modes. Web developers are advised to use standards-based alternatives for these effects. The most popular filters can be replaced with CSS3 features including: alpha-channel colors, opacity, linear gradients, box-shadow, and text-shadow. PNG images with transparency can replace the common use of AlphaImageLoader. SVG Filter Effects can be used to implement more complicated effects. These legacy filters are still available in IE10 in legacy modes 5, 7, 8, and 9 though their performance is inferior to standards-based alternatives.
Web Worker Profiling
When profiling an application with the F12 developer tools, you will only see activity from web workers that were started after you began profiling. To work around this issue, make sure the profiler is started before the worker(s) you want to profile.
Placing comments before the DOCTYPE declaration incorrectly puts IE10 into quirks mode.
Platform Preview setup shows an error dialog if you have open windows of older Platform Previews
If you have open windows of older Platform Previews running while you install the latest available Platform Preview, you will see an error dialog during setup. To avoid this issue, please close all open instances of the Platform Previews and re-run the newest Platform Preview installer.
Platform Preview Build opens links to *.EXE files as text
Description: When you click a link to an executable (.EXE) in the Platform Preview, it will open in the Platform Preview as a text file. To work around this issue: Right click the link and choose "Save Target As..." to save the linked file to your machine, after which you may run it. For more information see connect issue 556100.
Downloads initiated by script do not function
There is no Information Bar (aka Gold Bar) in Platform Preview. As a result, downloads initiated by script will not function. Files can be downloaded using the “Save Target As…” in the right-click context menu, by clicking on hyperlinks to files, and by typing a download URL in the Open dialog (Ctrl+O).
Upgrading the Platform Preview Build turns the taskbar pinned icon into a blank page icon
When a user upgrades from one version of the Platform Preview Build to the next, the taskbar pinned icon to turns into a blank page icon. As a workaround you can right click the icon on the taskbar and select "Unpin this program from taskbar". Open the Start Menu, right click the newly installed Internet Explorer Platform Preview under All Programs, and click "Pin to Taskbar". For more information see connect issue 556106.
CSS Grid and CSS Flexbox do not currently support anonymous text blocks
A temporary workaround is to wrap such blocks with an explicit element.
Layering is not currently supported in CSS3 Grid
The CSS calc() function is not currently supported for CSS3 multicolumn properties
Absolutely positioned elements contained within a multicolumn element may be positioned incorrectly if they are encountered after the multicolumn fragment in which they should be positioned
Borders may be drawn outside of the border box when specified on a CSS Grid item