ICO to BMP Converter
Some old programs, embedded devices and school assignments expect a plain bitmap rather than a modern image or an icon container. This page takes your ICO, reads it in your browser and writes a standard BMP. Transparent areas are filled with a colour of your choice.
How to convert ICO to BMP
- Add your ICO files by dropping them, clicking the drop zone or pasting.
- The output format is already set to BMP. Adjust quality or size if you need to.
- Press Convert and compare the original and new size for each file.
- Download each file or all of them as a ZIP.
When to convert, and when not to
- A legacy program or device wants a BMP and you only have an icon.
- You are following a tutorial or assignment that specifies bitmap input.
- You need a flat, uncompressed picture for a simple pipeline.
- Do not use BMP for the web or for sharing; it is large and has no transparency.
What changes
- The image the browser shows from the ICO, usually the largest or default entry, becomes the bitmap. Not every embedded size may be reachable.
- Output is 24-bit and uncompressed, so even a small icon creates a file bigger than you might expect for its pixel count.
- BMP here has no transparency. Transparent regions are filled with the background colour you pick, white by default.
- No quality slider applies because nothing is compressed.
- Metadata is not carried over.
Why the background colour matters
Icons nearly always rely on transparency. A bitmap in this tool does not, so the converter paints the see-through pixels with your chosen colour before writing the file. If the bitmap will be shown on a particular coloured surface, pick that colour; otherwise white or a neutral grey is a safe default.
Soft, anti-aliased edges were blended against transparency in the original. Placed on a very different colour, they can show a faint fringe. Try the colour you will actually use.
What a bitmap from this tool looks like inside
The BMP is written as a plain 24-bit image: three bytes per pixel with rows padded to a multiple of four bytes, and no compression. That plainness is the point. It is easy for simple programs to read, which is why legacy software still asks for it.
If a program refuses the result, check whether it expects a different bit depth or a particular variant. This tool only writes the 24-bit form.
Enlarging an icon first
If your target program needs a bigger bitmap than the icon provides, use the Resize option. Scaling up will make the picture larger but not sharper. For clean large artwork, go back to the original logo file.
Bitmaps from this tool are as plain as they come. That is exactly what some firmware, hobby projects and teaching examples want: no compression, no metadata, no surprises. If your target describes a different bit depth, you will need to adjust it in a dedicated editor after conversion.
For best results, pick the background colour deliberately. A transparent icon placed on a black screen will look wrong with a white fill, so choose the colour of the surface where the bitmap will actually appear.
Privacy: your files stay on your device
- The tool decodes, resizes and encodes your pictures with your browser. The files are never sent to a server.
- To check it yourself: open the browser developer tools (F12), open the Network tab, convert a file, and look for any request that carries your image. You will see none.
Frequently asked questions
Does the BMP keep transparency?
No. Transparent areas are filled with the background colour you choose.
Why is the BMP so big for a small icon?
Bitmaps are uncompressed, so every pixel takes up space.
Can I choose a size from the icon?
The browser chooses which embedded image it shows, usually the largest or default. You can then resize the result.
Will old software open the file?
A standard 24-bit BMP is widely supported, but a program with unusual requirements may still complain.
Is the icon uploaded?
No. It stays in your browser.