Convert BMP to ICO
Turn BMP images into ICO icons for favicons and Windows. Everything happens in your browser, so your images never leave your device.
Why convert BMP to ICO?
BMP files are usually uncompressed, so they're far larger than they need to be and awkward to share. ICO is the format browsers look for at /favicon.ico and the one Windows uses for app and shortcut icons.
The background stays as it is
BMP has no transparency, so the ICO keeps the same solid background. ICO supports transparency, but a converter can't tell which pixels are "background". To get a transparent ICO, remove the background in an editor first.
Favicons and Windows icons
Browsers still request /favicon.ico from websites, and Windows uses ICO for application and shortcut icons. Icons are square and the ICO format tops out at 256 × 256 pixels, so a square, simple BMP works best; fine detail disappears at 16 × 16.
BMP and ICO compared
| Property | BMP | ICO |
|---|---|---|
| Compression | Usually uncompressed | Lossless |
| Transparency | No | Yes |
| Animation | No | No |
| Typical file size | Very large | Tiny |
| Best for | Legacy and embedded software | Favicons, Windows icons |
| Support | Desktop apps; rare on the web | Browsers (favicons), Windows |
Questions
Will converting BMP to ICO make the background transparent?
No. BMP has no transparency, so the ICO keeps the same solid background. Remove the background in an editor first if you need a transparent ICO.
Will converting BMP to ICO reduce quality?
ICO stores icons losslessly, but the format tops out at 256 × 256 pixels, so start from a square BMP at that size or below and keep the design simple enough to read at 16 × 16.
Are my BMP images uploaded anywhere?
No. The conversion runs in your browser, on your own device, so your images are never sent to a server. Once the page and converter have loaded, it keeps working even if your connection drops.