What is ICO (Windows Icon)?
ICO is the icon format used for Windows programs and website favicons.
Modern sites can use PNG favicons, but classic favicon.ico files are still requested by many tools and crawlers.
File extensions: .icoMIME types: image/x-icon, image/vnd.microsoft.icon
Advantages
- Accepted as favicon by all browsers
- Supports transparency
- Can hold several sizes
Disadvantages
- Maximum size 256 by 256 pixels
- Rarely useful outside icons
- Few tools to edit it
Typical uses
- Website favicons
- Windows application icons
- Desktop shortcuts
Compatibility
All browsers and Windows read ICO; other systems usually prefer PNG icons.
Convert ICO to another format
Convert to ICO from another format
Frequently asked questions
Are my files uploaded to a server?
No. The conversion runs entirely in your browser with local code. Your files never leave your device, and there is no upload.
Is there a file size limit?
There is no limit on our side, but your browser memory is. Images work for very large files; for videos, files above a few hundred megabytes can fail on devices with little memory.
Will the quality suffer?
That depends on the target format and settings. Use the quality option to balance size and detail; lossless targets keep everything the source contained.
Which browsers are supported?
Current versions of Chrome, Edge, Firefox and Safari. Fast hardware paths are used where available, with a compatible fallback otherwise.