How to Enable HiDPI Mode in Mac OS X
The magic of Apple’s “Retina” displays is that OS X renders the user interface with four times as many pixels (twice the vertical and twice the horizontal resolutions) as it does on a traditional lower resolution display, giving users the benefits of ultra-sharp text and graphics without making the interface too small to see. This works great on high resolution displays like 4K monitors and the new 5K iMac, but what if you could have the benefit of Retina-like sharpness on a non-Retina monitor? Well, thanks to something called HiDPI mode in OS X, you can, although there’s a pretty big caveat.
HiDPI mode was initially available as an option in Xcode’s Quartz Debug utility, but since Mavericks has been accessible via a Terminal command. If you’re running Mountain Lion or older, check out this article at OS X Daily for instructions on how to enable HiDPI mode in OS X. If you’re running Mavericks or newer, including the latest El Capitan betas as of the date of this article, continue with the steps below.
First, fire up a new Terminal window and then copy and paste the following command:
sudo defaults write /Library/Preferences/com.apple.windowserver.plist DisplayResolutionEnabled -bool true
Press Return to execute the command and, because this is a “sudo” command, enter your admin password when prompted. Next, reboot your Mac and, upon logging back in, head to System Preferences > Displays.
Here, you’ll see the familiar preference window where you can set your resolution and refresh rate. Most users will likely have the “Default for Display” option checked, which is typically your display’s native resolution. Click Scaled to reveal additional resolutions and you’ll see one or more options at the bottom of the list with “(HiDPI)” appended to their resolutions. Click on one of the HiDPI modes to enable it on your desired display.
Note: If you’re not seeing the HiDPI resolutions listed in System Preferences after using the Terminal command above, try clicking on the “Scaled” radio button while holding the Alt/Option key on your keyboard. This trick reveals additional resolutions for all displays, and should list the HiDPI resolutions if they weren’t already visible.
You’ll instantly see everything appear much sharper, but here comes the caveat: your effective resolution is much lower. This works on high-resolution Retina displays because OS X has millions of additional pixels to work with. If you want “Retina-quality” on a standard-resolution display, you’re going to end up with a much lower effective resolution. For example, here’s what a native resolution of 1920×1200 looks like on a 20-inch iMac:
And here’s what HiDPI mode looks like with an effective resolution of 960×600:
Although it may be difficult to discern on your own display (you can click on each image to view them larger), the HiDPI mode makes OS X and apps look much crisper, but significantly reduces the working resolution of the system. You therefore likely won’t want to work in HiDPI mode all the time, but once you’ve enabled it with the Terminal command, you can easily switch to it when you want to view a particular app or document with Retina-like quality, or if you want to temporarily make the UI easier to see from a distance without the reduction in quality that accompanies using a “normal” lower resolution, such as when displaying OS X on an HDTV across the room.
When you want to switch back to the default native resolution, just head back to System Preferences > Displays and choose “Default for Display” or your preferred resolution from the “Scaled” list. It doesn’t hurt to leave HiDPI mode enabled as an option in OS X when you’re not using it, but if you want to remove the HiDPI mode resolutions from your “Scaled” resolutions list, just run the following command in Terminal:
sudo defaults delete /Library/Preferences/com.apple.windowserver.plist DisplayResolutionEnabled
Just as when you enabled HiDPI mode in OS X, you’ll need to both enter your admin password and reboot your Mac for the change to take effect.
There’s an App for That
If you’d rather not play around with Terminal commands, there are third party apps and utilities that can enable HiDPI mode for you, in addition to other display-related functionality. Examples include ResolutionTab ($1.99, Mac App Store) and SwitchResX ($15, shareware). SwitchResX in particular offers tons of additional functionality for setting up custom resolutions and refresh rates, but both of these apps can get you in and out of HiDPI mode with just a click.
HiDPI mode certainly isn’t a replacement for a true high-resolution Retina display, but it serves a useful role for those who occasionally need OS X to look sharper, such as when taking high-quality screenshots, or for users who want a larger and easier to read interface without the blurriness of a standard lower resolution.