Internet Explorer for Xbox 360 Technical Considerations

This topic provides an overview of developer features, technical considerations, and debugging and testing for Windows Internet Explorer for Microsoft Xbox. It contains the following sections:

• Technical considerations
  • Supported features
  • User-agent header / string
  • Fonts
  • Memory
  • Panning and scrolling
  • JavaScript performance
  • Media formats
  • Extensions: Plug-ins, ActiveX, and downloads
• Debugging and testing
  • Disable ActiveX controls
  • Layout
  • User-agent string
• FAQ
• Related topics

Technical considerations

Supported features

Internet Explorer for Xbox has the same HTML5 features as Windows Internet Explorer 9 for Windows, except for the changes shown here:

For a complete list of features that are supported in Internet Explorer for Xbox, refer to:

• Internet Explorer 9 Guide for Developers, except sections on UA string, Pinned Sites, and Developer Tools, which aren't applicable to Internet Explorer for Xbox
• A Quick Guide to Internet Explorer 8 Developer Features, except sections on Web services (Accelerators & Web Slices), Accessibility Protected Mode API, User Control, and Developer Tools, which aren't applicable to Internet Explorer for Xbox
• Internet Explorer Standards Support Documents

User-agent header / string

Compatibility View is a mode of Internet Explorer that allows webpages that were written for older versions of web standards to work correctly. In Internet Explorer for Xbox, Compatibility View is only enabled if a website is contained in a list of sites that is updated by Microsoft. For more info about the Compatibility View List, see Understanding the Compatibility View List. When Compatibility View is enabled on a website, a different user-agent string is sent to the website.

Users with standard definition (SD) televisions, which are lower-resolution, might use the mobile versions of websites. Users can do this in Internet Explorer for Xbox settings ("Use web pages formatted for mobile devices"). This also changes the Internet Explorer for Xbox user-agent string.

Here are the user-agent strings that are sent by Internet Explorer for Xbox.

Appropriate usage of the user-agent string

Great websites work well across different browsers and form factors. The best way to build code that works across browsers is to do feature and behavior detection. For example, don't assume that a feature exists based on the user-agent string alone. To learn more about feature and behavior detection, see Same Markup: Writing Cross-Browser Code.

If you're building a separate website for Internet Explorer for Xbox, for example, a TV-formatted experience, checking for the "Xbox" token in the user-agent string might be an appropriate way to redirect to your TV-formatted website.

Fonts

Downloadable fonts are supported via the Cascading Style Sheets (CSS) @font-face feature. The supported font formats are Web Open Font Format (WOFF) and TrueType (TTF). The Embedded OpenType (EOT) format isn't supported.

Memory

The Xbox console has 512MB of total system memory. Video and system memory are shared. Additionally, there's no virtual memory, and the Xbox hard drive isn't used as a paging mechanism. This is significantly less memory than is available on modern desktop and laptop computers.

It's possible to construct a webpage that requires too much memory to load. Large image elements might not render, or in extreme cases, the browser might exit and return the user to the Xbox home screen. Make sure that your website functions well, and that all resources load correctly.

If your webpage isn't loading, try these steps to minimize memory usage:

• Reduce the resolution of your image resources. By reducing image resolution, your images will download faster, and use less memory. If the display size of the reduced resolution image is too small, you can use CSS to stretch an image back to the original display size. Make sure that you rescale your image using an image editing tool – simply scaling the image down via CSS, or changing formats from .png to .jpg won't reduce memory usage.
• Only use one video tag. There is an overhead memory cost for each video element on a page. You can use a single video element and modify it as necessary (change its position, change the video src attribute, and so on).

Panning and scrolling

Avoid the use of CSS position:fixed, especially on pages that pan or scroll. These elements interfere with smooth scrolling and panning by forcing the page to re-layout during panning and scrolling.

Internet Explorer for Xbox makes it easy for users to pan and scroll webpages with push scrolling, which automatically scrolls the webpage when the user pushes the cursor to the edges of the screen.

Avoid using div or iframe for scrolling content. Use the body element of your webpage to contain scrolling content. Push scrolling doesn't work with sub-scrolling elements. Users must use the right thumbstick to scroll subscrollers.

JavaScript performance

Internet Explorer for Xbox uses the JavaScript engine for Internet Explorer for fast JavaScript interpretation. However, it doesn't have JIT (Just In Time) compilation, so some JavaScript operations might take longer compared with Internet Explorer for Windows.

Internet Explorer for Xbox also contains performance enhancements for smooth panning and scrolling. To maintain smooth panning and scrolling on your webpage, limit the use of JavaScript that responds to scroll events.

Media formats

Audio and video support are available via the HTML5 audio and video tags. For video, the H.264 format is supported. For audio, MPEG-Layer 3 (MP3) and AAC are supported.

For optimal video performance, we recommend that you encode your video using the H.264 "high" profile at 720p resolution.

Extensions: Plug-ins, ActiveX, and downloads

Plug-ins, like Microsoft ActiveX controls, Browser Helper Objects (BHOs), Toolbars, and Explorer bars aren't supported in Internet Explorer for Xbox. HTML5 audio and video are available for high quality media experiences.

File downloads and executable programs aren't supported. All file downloads are blocked.

Debugging and testing

To develop and debug your website for Internet Explorer for Xbox, you can use Internet Explorer 9 on Windows.

Disable ActiveX controls

Because Internet Explorer for Xbox doesn't support plug-ins, you'll want to make sure that you disable any ActiveX controls, such as Microsoft Silverlight or Adobe Flash. To do that easily, turn on ActiveX filtering.

In Internet Explorer 9:

1. Click Safety, and then click ActiveX Filtering.
2. Reload your webpage by clicking the Refresh button.

You can turn off ActiveX filtering by following the same steps.

Layout

Be sure to test your size at a variety of zoom levels, as these will be automatically adjusted on the Xbox based on the user's TV type and connection.

In Internet Explorer 9, click Tools, click Zoom, and then click Custom….

Test a range of zoom levels from 100% to 185%.

User-agent string

You can change the user-agent string in Internet Explorer 9 by using the developer tools:

1. Press F12.
2. Click Tools, select Change user agent string, and then click Custom….
3. In the Friendly Name field, type "Xbox: desktop, CV off".
4. In the User Agent String field, type "Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0; Xbox)".
5. Click Add.
6. Click Set.

FAQ

Q: Can users manage their own cookies?

A: Yes. Users can delete their cookies and all their browsing history in Settings.

Related topics

Internet Explorer for Xbox Developer Guide