App icon sizes explained: every size, and why there are so many

An app has one icon and ships thirty files of it. The reason is that screens differ in pixel density and platforms crop icons into different shapes, so each context needs a version rendered at exactly the right pixel size — and store review will reject a submission missing one. This guide explains the sizes so the list stops looking arbitrary; the app icon generator produces them from a single artwork.

Why one icon becomes thirty files

Two things multiply. Contexts: the home screen, settings, notifications, Spotlight, the store listing, the launcher, the task switcher — each shows the icon at a different physical size. Densities: a 60-point icon on an iPhone needs 120 pixels on a 2× screen and 180 on a 3×; Android spans 1× to 4× (mdpi to xxxhdpi). Vector icons would solve this, and both platforms now accept some vector formats, but the store assets and older devices still want bitmaps, so every size gets rendered — properly downsampled from a large master, never upscaled.

iOS: points, scales and the 1024

Apple specifies icons in points times a scale factor: iPhone app icon 60 pt at @2x and @3x (120 and 180 px); iPad 76 pt @2x (152) and iPad Pro 83.5 pt @2x (167); Spotlight 40 pt (80, 120); Settings 29 pt (58, 87); notifications 20 pt (40, 60). Plus the App Store icon at 1024×1024, which must be opaque (no alpha channel) and square with no rounded corners — iOS applies its own mask. Newer Xcode versions can generate the smaller sizes from the 1024, but the asset catalog still lists them and many pipelines ship them explicitly.

Android: densities and adaptive icons

Launcher icons are 48 dp: 48, 72, 96, 144 and 192 px for mdpi through xxxhdpi, in mipmap folders. Since Android 8, adaptive icons separate a foreground and a background layer at 108 dp, and the launcher masks them into a circle, squircle, rounded square or teardrop depending on the device — so anything important must sit inside the central 66 dp "safe zone", or it gets cropped on some phones. The Play Store wants a 512×512 icon, opaque, with its own rounding applied by the store. Google's design guidance has the full specification.

Web apps and favicons

A web app manifest lists icons for install prompts and home screens — commonly 192 and 512 px, plus "maskable" versions with the artwork inside a 10% safe margin so Android can crop them like adaptive icons. Favicons are the browser-tab cousin: a 32×32 (and 16×16) .ico or PNG, a 180×180 apple-touch-icon for iOS bookmarks, and an SVG favicon where supported. The favicon generator handles that set; Social media image sizes and aspect ratios the rest of the brand-image zoo.

Designing an icon that survives

• Start big and simple. A 1024-px master with one bold shape; detail that reads at 1024 vanishes at 40.
• No text smaller than a couple of letters — unreadable below 120 px.
• Keep the subject centred inside the safe zone; let the background layer extend to the edges.
• Test at 40 and 48 px on a real screen, and against both light and dark backgrounds.
• Don't upscale. A 512-px source blurred to 1024 fails review; upscaling a logo is a last resort, and a vector export is the fix.