ICO to ICNS

Convert Windows ICO icon files to macOS ICNS format. Perfect for cross-platform development, migrating icons from Windows to Mac, or creating universal app icons.

Drop your ICO file here

or click to browse files

Supports Windows ICO files up to 5MB

How to Convert ICO to ICNS

  1. Upload your Windows ICO file using drag & drop or the file browser.
  2. The tool will analyze your ICO file and show available sizes.
  3. Choose a size preset: Standard Mac, Retina, App Icon, or All Sizes.
  4. Configure macOS options like Big Sur rounded corners and padding.
  5. Select a scaling method for best results when resizing.
  6. Click "Convert to ICNS" to generate your Mac icon.

Why Convert ICO to ICNS?

Cross-Platform Development

Building apps for both Windows and Mac? Convert your Windows ICO icons to ICNS for a native Mac experience.

Platform Migration

Moving from Windows to Mac? Bring your favorite icons with you by converting them to the native Mac format.

Multi-Size Extraction

ICO files contain multiple sizes. We extract the best quality version to create crisp ICNS icons for all Mac displays.

Custom Mac Icons

Use your Windows favicon or app icon as a custom folder icon in Finder or for personal Mac applications.

ICO vs ICNS Format Comparison

Feature
ICO (Windows)
ICNS (macOS)
Platform
Windows
macOS
Max Size
256×256
1024×1024
Retina Support
Limited
Full @2x
Transparency
Yes
Yes
Image Format
BMP/PNG
PNG/JPEG2000

Frequently Asked Questions

Standard ICO files contain sizes like 16×16, 24×24, 32×32, 48×48, 64×64, 128×128, and 256×256. Our converter detects all available sizes and uses the largest one for the best quality conversion to ICNS.

If your ICO file contains a 256×256 image or larger, we can create crisp ICNS icons up to that size without quality loss. For sizes larger than your source, we use advanced scaling algorithms (Lanczos) to maintain quality.

Both ICO and ICNS formats support full alpha channel transparency. Your transparent backgrounds will be preserved during conversion unless you specifically apply a background color or rounded corners effect.

Open the ICNS file in Preview, press Cmd+A to select all, then Cmd+C to copy. Right-click any folder or app, choose "Get Info", click the icon at top left, and press Cmd+V to paste your custom icon.

Yes! Favicons are typically ICO files. However, favicons are usually small (16×16 to 48×48), so the resulting ICNS may appear pixelated at larger sizes. For best results, use a high-resolution ICO file.