User Agent Mozilla/5.0 (Windows NT 6.2; WOW64; rv:25.0) Gecko/20130628 Firefox/25.0 Build ID: 20130628031149 I tested it on Windows 8 tablet for latest nightly from ftp://ftp.mozilla.org/pub/mozilla.org/firefox/nightly/latest-mozilla-central/firefox-25.0a1.en-US.winн32.installer.exe STR: Download and Install latest Firefox. Set Firefox as default browser. Click on Firefox APP. Metro Firefox will open. Open any website. Hold the device in landscape view. Rotates the device to portrait view. Actual Result: Metro Firefox web content and any browser interface elements didn't change for portrait view. Expected Result: Metro Firefox web content and any browser interface elements should quickly adapt in the new view.

Is the Windows option to auto rotate on? Does IE10 auto rotate when you do this?

(In reply to Brian R. Bondy [:bbondy] from comment #1) > Is the Windows option to auto rotate on? Does IE10 auto rotate when you do > this? Brian,Windows option to auto rotate was not on. I changed it to "on". Now, It is working. IE10 and FX nightly also auto rotate as expected.

Thanks for checking!