How to fix blurry text in macOS applications

macOS is my operating system of choice, so when I’m working on projects that use a GUI I like to build macOS application bundles. This allows me to have some flexibility when it comes to running the app. However, every time I run these bundles for the first time the text in the app is blurry, and I keep forgetting why that happens.

This problem will inevitably come up again, so I’m documenting the solution here. I can’t say I’m very interested in spending hours searching for a solution. Again. Sigh.

Solution: support high resolution displays

Add this to your Info.plist

<key>NSHighResolutionCapable</key>
<true/>Code language: HTML, XML (xml)

such that the file will look something like this

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>NSHighResolutionCapable</key>
    <true/>
</dict>
</plist>Code language: HTML, XML (xml)

There will be other items in the file, but that’s where you want the key-value pair to be; in the dict object.

If you’re using PyInstaller like I currently am, you can add this to the info_plist dict in the specification file:

app = BUNDLE(
    info_plist={
        "NSHighResolutionCapable": True
    }
)Code language: PHP (php)

Why is this necessary?

macOS uses the Information Property List (Info.plist) to identify various capabilities of the app in question, including whether your app supports high resolution displays via the NSHighResolutionCapable property. I imagine the text looks blurry because macOS renders the app at low resolutions when the property is not defined or is set to False.

So by setting the property to True you’re letting macOS know that “hey it’s ok to render this app at higher resolutions”. Once the app is rendered at a higher resolution the text will no longer be blurry! Success!