App icon sizes for iOS and Android, without the spreadsheet

The first time you ship a mobile app, the icon requirements read like a tax form. iOS wants one ladder, Android wants another, and if you also run a web app there is a third. None of it is hard. It is just tedious, and easy to get slightly wrong.

What iOS asks for

Apple scales one artwork across a range of contexts: the notification badge, settings, spotlight, the home screen, and the App Store listing. In practice that means a run of PNGs from 40 pixels up to the big 1024 store image, at 2x and 3x densities. You do not draw them by hand. You draw one 1024 square and let a tool render the rest.

What Android asks for

Android thinks in density buckets rather than exact pixels. The names give it away: mdpi, hdpi, xhdpi, xxhdpi, xxxhdpi. Those land at 48, 72, 96, 144, and 192 pixels. Add a 512 image for the Play Store and the launcher is covered.

One more note. Android also supports adaptive icons, where the system masks your art into a circle, a squircle, or whatever the launcher prefers. If that matters to you, leave a little room around the edges so the mask does not clip anything important.

What a PWA asks for

An installable web app is the simplest of the three. A 192 and a 512, declared in the manifest, do the work. The 512 also becomes the splash screen, so give it a clean render.

Making the whole set at once

Pick a square source, ideally 1024 pixels, and hand it to the app icon generator. Tick the platforms you are shipping to, and it renders every size, names each file the way the platform expects, and zips the lot. For a Mac build, the ICNS converter packs the desktop sizes into a single .icns. When that same square also needs a browser favicon, the ConvertICO home converter turns it into an .ico.

Keep one high-resolution source and generate from it every time the art changes, instead of chasing individual pixel sizes by hand.