Convert ICO to ICNS on Mac
Convert ICO files to ICNS format on your Mac with Jollycat. Windows icon format containing multiple image sizes in a single file. Required for Windows application icons and favicons. All processing runs locally on your Mac — no cloud processing and no uploads required for conversion.
ICO vs ICNS
| Property | ICO | ICNS |
|---|---|---|
| Type | lossless | lossless |
| Compression | PNG or BMP embedded | PNG or JPEG 2000 embedded |
| Transparency | Yes | Yes |
| Animation | No | No |
| Bit Depth | 8/32-bit | 8/32-bit |
| File Extension | .ico | .icns |
| Key Advantage | Multiple sizes in one file | macOS standard icon format |
How to Convert ICO to ICNS on Mac
Open your ICO file
Drag and drop your .ico file onto the Jollycat icon in your macOS dock or menu bar. Jollycat instantly detects the format.
Select ICNS format
Pick ICNS from the list of output formats. Optionally adjust quality, resolution, or compression settings.
Convert and save
Click Convert and Jollycat processes the file instantly on your Mac. No uploads required, no waiting — everything runs locally on Apple Silicon.
When to Convert ICO to ICNS
ICNS advantages
macOS standard icon format. Retina display support.
ICO limitations
Limited to 256x256. Windows-centric format.
Common use cases
macOS app icons, Dock icons, macOS development.
ICO to ICNS Conversion Tips
ICNS bundles multiple image sizes from 16x16 to 1024x1024 for standard and Retina displays.
Frequently Asked Questions
Is the ICO to ICNS conversion free?
Jollycat is a one-time purchase for $9.99. Once purchased, you can convert ICO to ICNS and use all 1,650+ conversion paths with no limits.
Does converting ICO to ICNS require an internet connection?
No. Jollycat processes everything locally on your Mac. Your ICO files never leave your device — all conversion happens offline using Apple Silicon.
Can I batch convert multiple ICO files to ICNS?
Yes. Drag multiple ICO files onto Jollycat and convert them all to ICNS at once. Batch processing is built in.
Ready to Convert ICO to ICNS?
Jollycat handles ICO to ICNS conversion and 1,650+ other format conversions. All offline on your Mac.
Get Jollycat for Mac