PNG to BMP Converter
A tool, device or course assignment wants a plain BMP, and your image is a PNG. This converter writes an uncompressed 24-bit bitmap in your browser. The main thing to decide is what happens to any see-through parts of the PNG, because BMP in this tool cannot keep transparency.
How to convert PNG to BMP
- Add your PNG 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
- Software or hardware you use only reads BMP files.
- You need raw, uncompressed pixel data.
- An instructor or specification asks for the bitmap format.
- For sharing or storage, keep the PNG, which holds the same pixels in much less space.
What changes
- The pixels are written without compression as a 24-bit BMP.
- Transparent parts are filled with the background colour you choose.
- File size grows with the pixel dimensions and is independent of content.
- Metadata is not kept.
- No quality slider exists, because nothing is compressed.
What replaces transparency
The BMP written here has three colour channels and no alpha. If your PNG has transparent regions, they must become a solid colour. White is the default, and you can change it in the options. Choose a colour that matches where the bitmap will appear, or the see-through edges may look odd.
Semi-transparent pixels, such as soft shadows, are blended with that colour, which gives a believable edge on a matching background.
Why BMP files grow so much
PNG compresses its pixels without loss, so graphics with flat colour can be tiny. BMP stores each pixel in full, so the file size is determined by width times height times three bytes, whatever the picture looks like. A simple logo that was a few kilobytes as PNG can become many times larger.
If space or transfer time matters, use the resize option to reduce the dimensions. That is the only lever for BMP size.
Checking the result on the target system
Some devices expect an exact resolution or a particular colour depth. This tool gives you a 24-bit image at the dimensions shown next to the file. If your target needs fewer colours or an exact frame size, finish the job in a dedicated editor after downloading.
Tips for matching the target system
Read the specification of the program or device that will open the BMP. Note the required pixel size, colour depth and whether it wants a particular orientation. This tool saves 24-bit colour and applies any phone rotation first, so the image appears upright.
If you must hit an exact frame size, scale to the closest size here and finish the job in an editor that supports canvas size changes. Test on the real device with one image before preparing the full set.
Storing and sharing bitmaps
Because BMP files are large, avoid e-mailing or archiving them in bulk. Keep the PNG for storage, create the BMP just for the system that needs it, and download as a ZIP when you have many files. The ZIP shrinks the transfer, although BMP data compresses unevenly.
One more reminder: because BMP has no transparency in this tool, convert PNG files that will sit on different backgrounds separately, each with a matching background colour. Doing this once per group avoids a visible rectangle around the picture when the bitmap is later placed on a coloured surface in the target program.
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
Can the BMP be transparent?
No. Transparency is replaced by your chosen background colour.
Is the picture changed in quality?
No. The pixels are written without compression.
Why is the file so large?
BMP stores every pixel in full.
How do I make it smaller?
Use the resize option to reduce width and height.
Is my file uploaded?
No, everything runs in your browser.
Should I keep the PNG after making a BMP?
Yes. The PNG holds the same pixels in far less space and keeps any transparency.
Can I convert a folder of PNG files to BMP at once?
Yes. Add the files together, press Convert, and download them one by one or as a single ZIP. Files are processed in sequence so that your browser stays responsive during large batches.