User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:53.0) Gecko/20100101 Firefox/53.0 Build ID: 20170518000419 Steps to reproduce: System: Windows 10 Professional Version 1703 Build 15063.413 (has also been happening since before Creators update) Main Display: 3840 x 2160 landscape with Windows DPI set to 150% Secondary Display: 1080 x 1920 portrait with Windows DPI set to 100% 1) Run Firefox 2) Browse to any web page (FireFox window opens on high DPI (150%), main display) 3) Move the FireFox browser window to a monitor with a different DPI setting (mine is 100%) Actual results: The FireFox browser windows content ends up being much larger in all windows. If I modify the "layout.css.devPixelsPerPx" setting in about:config from "-1.0" to "1.0", the FireFox browser window's content looks 'normal'. However, if at this point I drag the window back over tot he high DPI display, the content is too small. Expected results: The FireFox browser window's content should have adjusted as it crossed the various monitors' DPI 'thresholds'. Chrome browser does this successfully.
Status: UNCONFIRMED → RESOLVED
Last Resolved: a year ago
Resolution: --- → DUPLICATE
Duplicate of bug: 1228570
I don't think this Windows issue is a dupe of a Linux issue. Widget has a very different implementation for each platform. That said, bug 890156 should have added multi-monito DPI support on Windows. I don't know why it does not work on reporter's system.
Status: RESOLVED → UNCONFIRMED
Resolution: DUPLICATE → ---
Component: Untriaged → Widget: Win32
Product: Firefox → Core
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