The macOS app icon shape, size and shadow
macOS icons carry their own rounded shape and shadow in a 1024px canvas. The template sizes, how to build an .icns with iconutil, and what differs from iOS.
An iOS icon is a full-bleed square that the system rounds. A macOS icon is different: the rounded shape, its edge and its shadow are part of your artwork. Deliver a full-bleed square for the Mac and it looks too large and flat in the Dock.
The template
| Part | Size on a 1024 canvas |
|---|---|
| Canvas | 1024 x 1024, transparent outside the shape |
| Rounded-square body | About 824 x 824, centred |
| Margin around the body | About 100px each side, for the shadow |
| Corner | A continuous rounded corner, not a simple radius |
Apple publishes design templates with the exact shape. Use them rather than drawing a rounded rectangle, because the corner is a continuous curve, and a plain border-radius looks slightly off beside system icons.
Shadow and depth
Mac icons have a soft shadow under the body, and many have subtle lighting on the surface. Keep the shadow inside the canvas. The transparency around the body is expected here, unlike on iOS, where it is an error; see iOS icons and transparency.
Building the .icns
mkdir MyApp.iconset
# icon_16x16.png, icon_16x16@2x.png, icon_32x32.png, icon_32x32@2x.png,
# icon_128x128.png, icon_128x128@2x.png, icon_256x256.png,
# icon_256x256@2x.png, icon_512x512.png, icon_512x512@2x.png
iconutil -c icns MyApp.iconsetTauri and Electron have their own ways to consume this; see icons for Electron and Tauri apps.
Small sizes still matter
The 16 and 32 point sizes appear in Finder lists and menus. Detail that looks good in the Dock turns to noise there. Check the small sizes before you ship, as in app icons at small sizes.
App Icon Foundry exports a macOS icon with the inset shape alongside the full-bleed iOS version, from the same design, so the Mac Dock and the iPhone home screen both get the file they expect.
Questions
What size is a macOS app icon?
The largest image is 1024 by 1024 pixels (512 points at 2x). Inside that canvas the rounded-square body is about 824 pixels wide, centred, with room around it for the shadow.
Why does my Mac icon look bigger than other apps?
It probably fills the whole canvas. Mac icons are inset, with transparent space around the rounded body. A full-bleed square looks oversized in the Dock next to icons that follow Apple's template.
How do I make an .icns file?
Put PNGs named icon_16x16.png through icon_512x512@2x.png in a folder ending in .iconset, then run iconutil -c icns on that folder. Xcode can also build it from an asset catalogue.