I needed to take some high resolution screen shots for a project I’m working on and didn’t know how to do it without tracking down one of my friends with a Retina MacBook Pro and offering to buy them lots of coffee. Turns out, there’s a system defaults setting that lets you turn it on. After some googling, I found this gist by Simone Manganelli with the magic incantations.

To enable the option, run this in the terminal:

sudo defaults write /Library/Preferences/com.apple.windowserver.plist DisplayResolutionEnabled -bool true

Update: Thanks to Wai Son Wong for pointing me to this stack overflow post about the change to the command in Mavericks.

You’ll need to log out and log back in for it to take effect. This doesn’t turn on the HiDPI mode, it just enables it in the Display preferences. For my poor little MacBook Air, I now have this choice:

Yes, that screenshot is full HiDPI resolution snapped from my MacBook Air1. And yes, running in 720x450 HiDPI is completely unusable for normal work. But now I can now take portions of screenshots in HiDPI on a non-retina MBA.

If you’ve got VMWare Fusion, you can get even more mileage out of this by running a Mountain Lion VM at a higher resolution. I’m able to run mine at 1280x800 HiDPI.

This is plenty for my purposes. I don’t know if this works on Parallels or not, but the principle should be the same. Just set up a Mountain Lion VM, set the system defaults, and then choose the higher resolution. Boom.

If you want to disable the option, run this in the terminal and everything will be as it was before:

sudo defaults delete /Library/Preferences/com.apple.windowserver.plist DisplayResolutionEnabled

Thanks for posting the gist, Simone!

Update: Looks like someone weaponized this power into an app. Check out Resolution Tab. Thanks to Vladimir Grichina for the note!