Windows – How to run Java apps upscaled on a high-DPI display

high-dpijavawindows 10

I'm trying to run a Java app (JAR file) on a high-DPI display on Windows 10. The app uses Swing and thus isn't DPI-aware. Normally when I run an application that isn't DPI-aware, Windows will scale it for me, albeit blurry. But for some reason it's not scaling the Java app; I just get a tiny little window in the corner with impossible-to-read text. How do I run a Java app with Windows' high-DPI (blurry) scaling?

Best Answer

The problem here seems to be that Swing is by default claiming that it is DPI aware, so windows doesn't scale it. Use this switch to turn off this behavior and windows will start scaling your swing app:


[EDIT: Unfortunately, this flag no longer seems to work in Java 8, I was testing it in Java 6. Looks like this is a known issue.]

[EDIT 2: You can modify a Java 8 install to work correctly, using a program to modify the EXE manifests. I changed the setting from true to false in the manifests inside of java.exe and javaw.exe, and now my Swing programs scale correctly in Windows 10 high dpi. I used Resource Tuner to this.]

[Edit 3] Just use Java 9