How to Set Custom Resolutions for External Displays in Mac OS X

Posted by Jim Tanous on March 17, 2016
mac os x custom resolutions

OS X normally handles display resolution and scaling quite well automatically, but those using external displays (particularly third-party displays) may wish to manually select their own resolution. Here’s how you can override OS X’s automatic and limited suggestions and choose any supported resolution for your external monitor.
To change the resolution of your Mac’s display, head to System Preferences > Displays. If you have more than one display connected to your Mac, a new Display Preferences window will appear on each display. Select the window residing on the display you wish to modify.
By default in recent versions of OS X, you’ll see a “default” recommended resolution for your external display, which includes high-resolution scaled “Retina” resolutions for 4K monitors. If you prefer a different resolution, OS X gives you four other options ranging from “Larger Text” (a lower equivalent resolution) to “More Space” (a higher equivalent resolution). The exact resolutions of the options offered will vary depending on the specifications of your external display.
mac os x system preferences resolution default
For example, the external monitor connected to our Mac in the screenshots is a 27-inch Dell P2715Q 4K monitor, with a native resolution of 3840×2160. OS X suggests a “default” resolution of a Retina-scaled 1920×1080 equivalent, and we have the choice to set other resolutions ranging from an equivalent of 1504×846 to the full 3840×2160.
While adequate for the majority of users, these five resolution options are missing a number of “in-between” resolutions as well as “low resolution” modes, such as a true 2560×1440 that must be upscaled by the monitor and may be necessary for testing or software compatibility purposes. Thankfully, these resolutions are still accessible, and here’s how to access them.
To access all supported resolutions for your external display, press and hold the Option key on your keyboard and then click the “Scaled” option again.
mac os x system preferences custom resolution
The row of five recommended resolutions will be replaced by a complete list of all supported resolutions. Those using a 4K display can also click “Show low resolution modes” to access the aforementioned low resolutions that will be upscaled via your display. If your Mac is connected to a television, this list may also include alternate refresh rates and display modes if supported by the hardware.
Once you’ve found your desired resolution, just click its entry in the list to switch your display. While your resolution choices will survive reboots, this complete resolution list isn’t always visible, and will revert to the default view after you close and reopen System Preferences. But just remember to click “Scaled” while holding the Option key the next time and you’ll be right back where you left off.

7 thoughts on “How to Set Custom Resolutions for External Displays in Mac OS X”

Guest says:
none of these resolutions are “custom”… I need to set mine to 1680×1050, but that’s not an option… that’s a “custom” resolution. This is not something I can do via the default system settings interface!
rai says:
I agree. I was disappointed when I read this article as I was hoping to find a way to actually set a CUSTOM (i.e. NON-BUILT-IN) resolution. I already know about this ALT/OPTION trick to display the hidden resolutions and it is not what I was looking for.
Art Witulski says:
I found that the new screen with the individual resolutions would only show up when the external monitor is plugged in, you can’t adjust it first and then plug the monitor in. I’m plugged thru a USB-C to HDMI adaptor to a large screen TV. In the normal scaled mode I get a tiny displays on the TV. When I do the option trick, I get the small tiny screen with additional resolutions and go down to about 1600 by 900 then everything is about the right size on the TV. I have Mojave 10.14.
Rae Lambert says:
Thanks for the info. Is there a way to set this as the new default so I don’t have to update it every time?
Josh says:
This seems to no longer work on my MBP Retina… it worked a few months ago!
Selva says:
Thanks Bro. Was struggling to change resolution on external monitor. Below helped
But just remember to click “Scaled” while holding the Option key the next time and you’ll be right back where you left off.
Rob says:
Thank you. I always forget about that option button!
Joe Holliday says:
I did this, but I’m still missing some resolutions that I know my monitor is capable of.
Przemator says:
Thanks for the tip! This helps me when using Citrix Receiver. Just one problem.
My display is 4K (3840×2160), however I don’t see the Full HD resolution (1920×1080) with the low resolution option.

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