JPG to BMP Converter
Some older programs, embedded devices and school or lab tools only accept plain BMP bitmaps. If you hold a JPG and need one of those, this converter writes an uncompressed 24-bit BMP right in your browser. Expect a big file: that is how BMP works, not a fault of the conversion.
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Free to use on any site. Paste the code where you want the tool to appear. It runs inside the page; visitors' files are processed in their own browser and are not uploaded.
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How to convert JPG to BMP
- Add your JPG 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
- Legacy software, a microcontroller project or a lab instrument will only read BMP.
- You need raw pixel data without any compression step to decode.
- A course assignment or tool specifically asks for bitmap files.
- For the web, e-mail or storage, keep the JPG instead, because BMP files are far larger.
What changes
- The image is saved as a 24-bit BMP: three colour channels, no compression.
- File size depends on width and height only, not on how detailed the picture is.
- BMP has no transparency here, and the background colour you choose is used if any area needs filling.
- Metadata is not kept, and phone rotation is applied first.
- There is no quality slider, because nothing is compressed.
Why BMP files are so large
A BMP stores every pixel as three bytes with no compression, so the size comes straight from multiplying the width by the height. A JPG of the same picture is compressed and discards detail to be small. Converting up to BMP removes the compression but cannot bring back the discarded detail, so you gain compatibility, not quality.
If a program will accept a smaller file, offer it PNG instead. PNG is lossless too, but compresses the pixels, which usually saves a great deal of space.
Making the pixel size match what the other program expects
Devices that need BMP often also need a particular resolution. Use the resize options to scale by a percentage or to a maximum width and height. The aspect ratio is kept, so you may need to crop or pad in another tool if an exact frame size is required.
Check the pixel dimensions displayed beside each finished file before you copy it to the target device. Reducing the size is also the only way to shrink a BMP, so it is worth doing when storage is limited.
Colour and bit depth
The output is 24-bit colour, which covers the full range of an ordinary JPG. It is not an indexed or monochrome bitmap. If your target needs 8-bit, 1-bit or a special palette, you will need a dedicated image editor after this step.
Where BMP files are still asked for
BMP survives in places that value simplicity: older Windows utilities, firmware tools that draw splash screens, some scientific and laboratory software, and teaching exercises that read pixels directly. The format has a tiny header and no compression, so a program can read it with very little code.
If you are not sure your target needs BMP, check its documentation or try a PNG first. Many programs that list BMP also accept PNG, which would save you a lot of space.
A final practical point: BMP has no place for metadata like a caption or copyright line, so anything you rely on from the JPG's embedded information will not travel with the bitmap. Keep the original JPG next to the BMP in your project folder so the context is not lost, and name the files clearly so you can tell them apart months from now.
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
Why is the BMP so much bigger than the JPG?
BMP is uncompressed. Its size depends only on the pixel dimensions.
Is it 24-bit or 32-bit?
It is a 24-bit BMP with no alpha channel.
Can I make the BMP smaller?
Reduce the pixel size with the resize option. There is no quality slider.
Is the image uploaded?
No, the conversion stays on your device.
Will the picture look the same?
Yes, it shows the same pixels as the JPG. No detail is added or removed.
Does the BMP include my photo's location data?
No. Metadata such as location and camera details is not written to the BMP.