Convert PNG to ICNS for macOS Apps (Xcode-ready icons)

If you build macOS apps, you eventually hit the “I only have a PNG, but I need an .icns” problem. The shortcut is to generate a multi-size ICNS file in one go, instead of hand-resizing files and hoping you didn’t miss a size.

Use the PNG to ICNS Converter and you’re done in a minute.

Quick steps (the short version)

1. Drop your PNG into the tool.
2. Include 128, 256, 512, and 1024 sizes (that covers most cases).
3. Download the .icns and add it to your Xcode asset catalog or packaging step.

PNG → ICNS tool UI

Example that matches real usage

Let’s say you have a 1024×1024 transparent PNG logo. The tool outputs a single .icns file containing:

• 128×128
• 256×256
• 512×512
• 1024×1024

That single file is what Xcode expects when you set the app icon in Assets.xcassets.

ICNS sizes preview

Common mistakes (and how to avoid them)

• Starting with a small PNG. If your source is 256×256, the 1024 size will look soft. Use the largest source image you can.
• Forgetting transparency. If the PNG has a white background, that’s what ends up in the final icon.
• Missing sizes. macOS still expects several sizes for crisp rendering at different scales.

Verification checklist

Before shipping:

• Preview the .icns locally and confirm each size exists.
• Check transparency on both light and dark backgrounds.
• Make sure the icon looks right in Xcode’s preview.

When to use something else

• Need a Windows app icon? Use PNG to ICO.
• Only need a single size? Keep the PNG and skip ICNS.