BMP to ICO
Convert a BMP bitmap to a multi-size ICO icon in your browser. Pick the sizes, clear a solid background, and download.
How to convert BMP to ICO
- Choose or drop a .bmp file. It is decoded by your browser and never uploaded.
- Keep the selected sizes (16, 32, 48 and 256 px) or click a tile to add or remove one.
- If the bitmap sits on a white or magenta box, turn on Make edge background transparent.
- Download the ICO. Every size is stored inside that one file.
Use the ICO
As a website favicon, upload it to your site root and add this to the HTML head:
<link rel="icon" href="/favicon.ico" sizes="any">For a Windows shortcut, open its Properties, choose Change Icon and browse to the file. Need Apple and Android icons as well? Use the favicon pack generator.
BMP to ICO questions
Why does my icon have a white box around it?
Most BMP files are 24-bit and have no transparency, so the background is part of the picture. The background option takes the color in the top-left corner and clears every matching pixel connected to the edges. Matching areas inside the artwork stay. A 32-bit BMP that already has an alpha channel keeps it.
Which sizes should the ICO contain?
16, 32 and 48 px cover browser tabs and most Windows views. 256 px is used for large and extra-large Explorer icons. Sizes marked Enlarged are bigger than your bitmap, so start from a larger image if you can.
Which BMP files work?
Standard Windows bitmaps, from 1-bit to 32-bit and RLE-compressed, decode in all current browsers. Up to 50 MB and 4096 × 4096 px. If a rare variant fails, re-save it as PNG and use PNG to ICO. Photos saved as JPEG belong in JPG to ICO.
Can I change an ICO later?
Yes. Resize an ICO file to change the sizes it contains, or extract its PNG images. Making a Mac icon from the result? Convert it with ICO to ICNS.