ICO vs ICNS vs PNG
Three formats cover almost all icon delivery: ICO for Windows, ICNS for macOS, and alpha PNG for Linux, Android, and iOS. They are not interchangeable - each targets a different platform - but you can produce all three from one master.
| Format | Platform | Container? | Max size in IconWorkshop | Transparency |
|---|---|---|---|---|
| ICO | Windows | Yes - multi-size | 768x768 | 32-bit alpha |
| ICNS | macOS (also RSC, BIN) | Yes - multi-size | 1024x1024 | Alpha |
| PNG | Linux, Android, iOS, web | No - single image | Exported per size | Alpha |
When to use each
- ICO - Windows application icons (
.exe,.dll), shortcuts, and folders. - ICNS - macOS application bundles, shown in Finder and the Dock.
- PNG - Linux desktops, Android and iOS app icon sets, web favicons, and store or marketing art.
One master, every format
Keep one high-resolution or vector master and let IconWorkshop package ICO, ICNS, and PNG from it, so every platform stays visually in sync. The focused guides cover the conversions: ICO to ICNS, SVG to ICO, and the iOS and Android app icon tutorial.
Common questions
Can one file work on both Windows and macOS?
No. Windows needs an ICO and macOS needs an ICNS - they are different containers. Build both from the same artwork; IconWorkshop converts between them in either direction.
Is a PNG enough for a Windows app icon?
No. Windows application and shell icons want an ICO so the shell can choose a size. PNG is the right delivery format for Linux, Android, iOS, and the web.
Where does WebP fit in?
WebP is a web and raster delivery format - IconWorkshop 6.97 adds WebP import and export - but it is not a Windows or macOS icon container. Use it for compressed web imagery, not as an app icon format.
Related guides
Build Cross-Platform Icons with IconWorkshop 6.97
Download the fully functional 30-day trial for Windows, or go straight to the perpetual license checkout.
Windows 7, 8/8.1, 10, and 11. One license per developer, lifetime support, one year of updates included.