Icon Composer: Any way to add icons to the app bundle for older macOS versions?

Developer Tools & Services Xcode Asset Catalog Xcode macOS Icon Composer

Created Jul ’25

Replies 21

Boosts 14

Views 1.8k

Participants 7

Several app developers are struggling with the inability to provide a separate app icons that looks nice on older macOS versions while at the same time provide Icon Composer icons that look great on macOS Tahoe 26. An ability to provide separate icons is super important to those who have app icons that follow the curvature of the default icon borders (as the corner rounding radius is different for Sequia and Tahoe). Take a look at this for example:

https://github.com/ghostty-org/ghostty/issues/7564#issuecomment-3042061547

Question: Is there a definitive/recommended way to address this issue? How can a developer add a glass icon variant that looks good on Tahoe and provide a bitmap icon for older macOS versions?

Some background info:

Prior to Xcode 26 beta 4, one could add an App Icon to Assets to be used as app icon for legacy macOS versions (Sequia and older) and use a new Icon Composer icon (placed in the project root) for macOS Tahoe 26. Enabling "Include all app icon assets" under target settings ensured that older macOS versions would use the old app icons while Tahoe the new Icon Composer glass one.

Since Xcode beta 4 this technique no longer works. Xcode instead insists on populating Assets.car with Icon Composer generated variants, disregarding the App Icon provided in Assets. Although the App Icon in Assets makes its way to a .incs file in the app bundle's Contents/Resources folder, but that is not used by macOS anymore and is there for some compatibility purposes. The Assets.car file (which matters) only contains the variants generated by Icon Composer and does not contain the png icons provided in the Assets.

Boost

Steve4442 OP

No solution afaik. I am still on Xcode 26.0.1 because of this.

My plan is to simply drop pre-Tahoe (and Intel) support for newer versions of my stuff when macOS 27 lands and leave all this mess behind. :)

filbercio OP

Thanks @Steve4442. I figured you'd be the one to respond:)

Ok, so dumb follow-up question: If I ditch Asset Catalog and use Icon Composer exclusively, is there a way to generate an icon such that the Liquid Glass effect is On for Tahoe, but Off for Sequoia and earlier?

In other words, have an Icon Composer Layered icon which automatically renders "flat" in Sequoia, but "glassy" in Tahoe?

I'm about 98% sure I can't, but I figured I'd ask in case I missed something really obvious.

Steve4442 OP

No, it does not seem to be possible. It would be great to have design elements or rendering options depend on macOS version (legacy vs 26+) in Icon Composer - this would eliminate all problems of course. But this feature is missing and by this time it is very unlikely Apple will improve the functionality in this regard.

filbercio OP

@Steve4442 Quick FYI: I actually have the 2 different icons working now (Liquid Glass Icon Composer .icon appears in Tahoe, and my current Legacy .icns appears in Sequoia). It's a huge mess to do, but it is possible.

In my case I had to:

Generate a Legacy .icns via Terminal (instead of using an Asset Catalog in Xcode)
Install Xcode 26.0.1
Create a simple test app with a Shell Script that runs actool to build the Asset.car file.
Build my test app with Xcode 26.0.1
Copy the resulting Assets.car and the Terminal-built .icns, into my Xcode 24.3 production project.
Tweak my Xcode 24.3 production project's Info.plist and build.
Final app displays two different icons: LG in Tahoe, Legacy in Sequoia.

To give you an idea of how messy this is, I had to follow much of John Siracusa's advice from here: https://mjtsai.com/blog/2025/08/08/separate-icons-for-macos-tahoe-vs-earlier/

If anyone really wants to go through this major hassle, I can try to write up instructions here. But it'll take me a while to write up the process and I'm not sure when I'll have the time to do that.

filbercio OP

My test projects for anyone who wants to try this madness. Requires installing Xcode 26.0.1. Follow the 2 Read Me files included. At some point I may clean this up and post it on Github. But Dropbox will have to do in a pinch:

https://www.dropbox.com/scl/fo/pyqw2s06pzc4gacdrysmf/AHp6Bqy7dzfGZz34jOoG6F0?rlkey=cziky74r2hwxfo9m4gpd6fpif&st=8z7au8wn&dl=0

If someone comes up with a cleaner way to do this, please share with the whole class:)

filbercio OP

Ignore my Dropbox post. I set something up in Github instead. I hope this helps someone:)

https://github.com/psulak/Tahoe-Sequoia-Hybrid-Icon