ICO Converter
Free ICO converter that runs entirely in your browser. No upload, no signup — convert to ICO or from ICO into 200+ supported formats in one click.
Drop any file here or click to browse
All file types supported
About ICO
ICO
ICO is the image container format used for Windows icons and favicons. A single ICO file can bundle multiple sizes and color depths so that the operating system can select the best resolution. ICO is still essential for desktop application icons and website favicons.
- Developer
- Microsoft
- Initial release
- 1985
- Compression
- Uncompressed
- Color depth
- up to 32-bit
- Transparency
- Yes
Best for
- Windows application icons
- Website favicons
- Bundling multiple icon sizes
- Desktop app icon resources
- Browser tab favicon images
Pros
- +Bundles multiple sizes and color depths in one file
- +Essential for Windows app icons
- +Supports transparency
- +OS selects the best resolution automatically
Cons
- −Limited to icon use cases
- −Not suited for general photography
- −Less universal outside Windows
- −No modern compression
How to convert with the ICO converter
- 1
Choose the ICO file you want to convert from your PC, Mac or mobile device, or simply drag and drop it onto the page.
- 2
When your file is uploaded, the output format is preset to ICO. You can add more files to batch-convert them together.
- 3
Click the gear icon and tweak codec, quality, resolution or other options if you need them, then apply to all files if you want.
- 4
Click the Convert button. When conversion completes, download the result to your computer or save it back to Google Drive / Dropbox.
Frequently Asked Questions
What is an ICO file used for?▼
ICO is the icon format for Windows apps and website favicons. It can bundle the same image at multiple sizes (16×16 up to 256×256) in a single file.
How do I make a favicon from my logo?▼
Convert your PNG or JPG to ICO here — drop your logo, and you will get a favicon-ready file for your website's browser tab icon.
Can an ICO file have transparency?▼
Yes, ICO supports alpha transparency, which is essential for icons that sit on varying backgrounds. Converting from PNG preserves it.
What size should a favicon ICO be?▼
Modern practice is to include 16×16, 32×32, and 48×48 pixels. Browsers pick the best size for tabs and bookmarks automatically.
Why can't I just rename a PNG to .ico?▼
ICO has its own container structure — renaming does not create a valid icon file. A proper conversion re-encodes the image into the ICO format.
Supported Conversions
Specific converters
100% Free
No hidden fees, no subscriptions, and no limits. Enjoy complete access to all features gratis.
No Signup Required
Start converting immediately without creating an account or sharing email address.
Private & Secure
Your files never leave your device. All processing is completed locally for maximum privacy.
Batch Conversion
Convert multiple files simultaneously to save time. Fast and efficient multi-file queue.
Runs in Browser
Utilizes advanced client-side WebAssembly technology to process files directly inside your tab.
200+ Formats
Supports a wide variety of formats including images, documents, audio, video, and more.
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