BMP to ICO Converter

What happens when you convert BMP to ICO

• The image is decoded and written as a PNG-based icon of up to 256 by 256 pixels.
• Icons are limited to 256 by 256 pixels, so larger images are scaled down to fit, keeping their proportions.

How to convert BMP to ICO online

1. Press "Choose BMP files" and select one or more files, or drag them onto the box. You can add files of any size your device can hold in memory.
2. Adjust the settings if you need to. The output is lossless, so there is no quality setting to worry about.
3. Press "Convert to ICO". Images convert in a second or two each.
4. Save each ICO with its download button. Close the tab and every trace of the files is gone from memory.

Why convert BMP to ICO?

BMP files usually come from Windows software, embedded displays and legacy tools. People convert them to ICO because ICO is the format browsers and Windows use for website and program icons.

In short, BMP is good at what it was made for, and ICO is the more practical choice when the file has to open, upload or print somewhere else. BMP opens in browsers and every Windows image tool, while ICO shown by browsers as a favicon; opening one directly depends on the viewer.

How to convert BMP to ICO on Windows, Mac, iPhone and Android

On Windows

Open this page in Chrome, Edge or Firefox, drag your BMP files in from File Explorer, and press Convert. Each ICO is saved to your Downloads folder.

On a Mac

Safari, Chrome and Firefox all work. Drag the BMP files from Finder onto the drop zone and the ICO files land in Downloads.

On iPhone and iPad

Open the page in Safari and tap Choose BMP files. You can pick from Photos or from the Files app. The converted ICO appears in Files, in the Downloads folder; to put it in your photo library, open it there, tap Share and choose Save Image.

On Android

Open the page in Chrome, tap Choose BMP files and pick them from Files or your gallery. The ICO is saved to the Download folder, where any file manager can find it.

Best settings for BMP to ICO

Icons are square by convention and can be at most 256 by 256 pixels. Choose 256 for modern Windows and high-resolution screens, 48 or 32 for classic desktop icons, and 16 or 32 for a website favicon. Non-square images are scaled to fit without being stretched.

BMP vs ICO: the differences

About BMP and ICO files

What is a BMP file?

BMP usually stores pixels with no compression at all, so a 12 megapixel photo is about 36 MB. That size is the price of being readable by almost any program ever written for Windows.

What is an ICO file?

An ICO file is a small container that can hold several sizes of the same icon, and since Windows Vista each size may be stored as an embedded PNG. The largest size an ICO can hold is 256 by 256 pixels.

BMP to ICO not working? Common problems

• Colours look slightly different. Browsers convert images to the standard sRGB colour space when they decode them, so wide-gamut and CMYK images can shift a little.
• A phone photo comes out upright even though it looked sideways elsewhere. That is correct: the rotation stored in the photo is applied during conversion, so the ICO is always the right way up.
• The file is bigger than expected. It depends on the settings. At the defaults, the ICO usually comes out close in size to the BMP; lower the quality for a smaller file.

Convert BMP to ICO from the command line

If you work in a terminal, ImageMagick converts BMP to ICO in one line:

magick input.bmp output.ico

To convert every BMP in a folder at once, use magick mogrify -format ico *.bmp. The converter on this page does the same job without installing anything.