BMP to ICON Converter
FileFlip converts BMP to ICON entirely inside your browser, using ImageMagick compiled to WebAssembly. The file is never uploaded to a server: it is read off your disk, converted on your own machine, and saved back by the browser. That means no file-size limit, no queue and no account.
How do I convert a BMP file to ICON?#
- Drop your BMP file onto the converter at the top of this page, or click it to pick one from your computer. You can add as many as you like.
- Leave the target set to ICON and the conversion starts on its own. FileFlip downloads 14.1 MB of WebAssembly the first time and nothing after that, then runs ImageMagick on your own machine.
- Save the ICON file. Your browser writes it straight to your downloads folder, because there was never a server holding it.
Does converting BMP to ICON lose quality?#
No. Converting BMP to ICON writes the data out again without discarding any of it, so nothing that was in the BMP file is lost on the way. What changes is the size of the file, not what is inside it.
Is it safe to convert BMP files online?#
Yes, because nothing is uploaded. FileFlip converts BMP files inside the browser tab you already have open, using WebAssembly builds of the same engines a desktop converter would install. Your file is read from your own disk into the page's memory, and no request carrying it is ever made.
You do not have to take that on trust. Open your browser's network panel, run a conversion, and you will see the engine come down and your file go nowhere. There is no upload, no server-side copy, no retention window, and no account tied to what you converted.
How FileFlip works lists every engine, its version and its download size, and shows how to check for yourself that nothing leaves your machine.
What BMP to ICON actually does to the file#
Converting BMP to ICON runs on ImageMagick, downloads 14.1 MB of WebAssembly the first time and nothing after that, writes the data out again without discarding any of it, keeps transparency.
| Engine | ImageMagick |
|---|---|
| Conversion path | One step: BMP → ICON |
| Downloaded to your browser | 14.1 MB, once, then cached by your browser |
| Quality | Lossless |
| You get back | One file |
| Where it runs | In a background worker, so the page stays responsive |
What survives the conversion
| What is in the file | This conversion | Why |
|---|---|---|
| Transparency | Kept | Carried through into the converted file. |
What is a BMP file?#
A BMP file holds a device-independent bitmap: a pixel grid stored with a Microsoft-defined header and, in the overwhelming majority of BMP files in the wild, no compression at all.
Use BMP when a Windows-native application, printer driver, or legacy tool specifically expects it, or when pixel data has to be stored with zero encoding overhead for a processing pipeline.
Convert BMP to PNG or JPEG for anything leaving that pipeline, since both produce a far smaller file and PNG matches BMP's lossless, generation-safe quality.
What is an ICON file?#
ICON is ImageMagick's alternate name for the ICO format, the container Windows uses for small multi-resolution images shown as application, file and shortcut icons, so a file written as ICON is the same Windows icon container as one written as ICO.
Use ICON, or the equivalent ICO, for Windows application icons, favicons and shortcut images, where the file needs to offer several sizes in one container.
Convert to PNG when a single-resolution image is needed for general use, since most software outside Windows icon contexts doesn't expect an ICO/ICON container.
BMP to ICON questions people ask#
Why does old Windows software still use BMP?
BMP has been part of the Windows GDI graphics API since the 1980s, so decades of Windows applications, printer drivers, and icon or wallpaper tools were built to read and write it natively without needing an external image library. That built-in support, plus the format's simplicity to decode, is why it has stayed in use in Windows-specific tooling even though it's a poor choice for sharing images.
Why are BMP files so much bigger than JPEG or PNG?
Most BMP files store every pixel's color value directly with no compression, so a BMP is close in size to the raw uncompressed image data. JPEG and PNG both apply compression, lossy in JPEG's case and lossless in PNG's, which is why the same photo saved as either is a fraction of the size of a BMP.
Can a BMP file be compressed?
Yes, though it's rare in practice. The BMP specification includes run-length encoding modes, RLE8 for 8-bit images and RLE4 for 4-bit images, that compress losslessly the same way GIF's LZW does, just less efficiently. Almost all BMP files encountered in practice still use BI_RGB, the uncompressed mode, because that is what most software defaults to writing.
Does BMP support transparency?
It can, but support is inconsistent. The BITMAPV4HEADER and BITMAPV5HEADER, both extensions to the original format, can store a 32-bit image with an alpha channel, but many image viewers, browsers, and older software ignore that alpha data entirely and render the image as fully opaque. PNG's alpha transparency is much more reliably supported across software.