PNG to ICNS converter
Make a macOS app icon from one PNG. You get a .icns with all ten sizes Apple defines, from 16×16 to 512×512@2x, ready for Xcode, Electron or Tauri.
| Slot | Pixels | Type code |
|---|---|---|
| 16×16 | 16 | icp4 |
| 16×16@2x | 32 | ic11 |
| 32×32 | 32 | icp5 |
| 32×32@2x | 64 | ic12 |
| 128×128 | 128 | ic07 |
| 128×128@2x | 256 | ic13 |
| 256×256 | 256 | ic08 |
| 256×256@2x | 512 | ic14 |
| 512×512 | 512 | ic09 |
| 512×512@2x | 1024 | ic10 |
Your icon appears here at each macOS size.
What’s inside an .icns
An .icns file starts with the 4 letters icns and the total file length, followed by a series of chunks. Each chunk has a 4-letter type code that tells macOS which size it is (ic07 is 128 px, ic10 is the 1024 px “512@2x” image) and holds a complete PNG. That’s the format iconutil produces, and it’s what this converter writes.
The @2x slots exist for Retina displays: a 32×32 point icon in Finder is drawn with 64 real pixels. Supplying every slot lets macOS pick an exact match instead of resampling.
Making a Windows icon too? Use the PNG to ICO converter with the “Windows app (16–256)” preset. For a website, the favicon generator makes the full web set.
Questions people ask
How do I convert PNG to ICNS?
Drop a square PNG (1024×1024 is ideal) into the converter and click Download .icns. Every size macOS needs, from 16 px to 1024 px, is generated in your browser and packed into one .icns file.
What size PNG do I need for an ICNS file?
A 1024×1024 PNG, because the largest slot in an .icns is 512×512 @2x (1024 px). Smaller sources work, but the large sizes will be upscaled and look soft.
How do I make an ICNS on a Mac without a website?
Create a folder named icon.iconset containing PNGs named icon_16x16.png, icon_16x16@2x.png and so on up to icon_512x512@2x.png, then run iconutil -c icns icon.iconset in Terminal. This page does the same thing in one step, and can also download the .iconset PNGs as a zip.
Where is the ICNS file used?
macOS uses .icns for application icons, in the Dock, Finder and Launchpad. Electron, Tauri and Xcode projects reference it in their build settings. Websites never use .icns; for a site use the favicon generator.
Should the macOS icon have a transparent background?
Yes, usually. macOS app icons since Big Sur are a rounded square with a soft shadow, drawn inside the canvas with transparent margins (about 100 px of padding on a 1024 px canvas per Apple’s template). Turn on “Apply macOS padding” to add that margin.