BMP to JPG

How it works

Tap or click the box and choose your BMP file; .bmp and .dib files are accepted and you can pick several. The tool first reads the file header: if the file is not a BMP or the header is damaged, it tells you before converting. It then opens the image with your browser's own decoder and writes it in the format you picked. JPG shrinks the file the most; transparent areas are placed on white, quality 90 is indistinguishable from the original and 70 gives a smaller file. PNG keeps every pixel identical; the saving is smaller than with JPG but still large. Because BMP is almost always stored uncompressed, the savings are dramatic. Example: a 4000×3000 pixel 24-bit BMP is about 36 MB; the same image as a quality-90 JPG usually comes down to a few megabytes. The result line shows the BMP size and the new size, the percentage saved, the pixel dimensions and the BMP's bit depth.

This tool is also known as bmp to jpg, bmp to png, convert bmp to jpg, bmp to jpeg converter, bmp converter online, reduce bmp file size.

What is BMP (bitmap)?

BMP is Windows' built-in image format: it stores the color of every pixel row by row, usually with no compression at all. That makes it easy to read but large; in a 24-bit BMP each pixel takes 3 bytes, so a 1920×1080 screenshot is about 6 MB. Images saved from Paint, output from older scanners and camera software, and screen captures from some machines and devices are still BMP. Converting to JPG or PNG makes them many times smaller for email, upload forms or sending from a phone.

What is Bit depth?

Bit depth is the number of bits used to store one pixel's color. In BMP, 1 bit means black and white, 4 and 8 bits mean a 16- or 256-color palette, 24 bits means full color and 32 bits means full color plus transparency (or an unused byte). File size follows directly: at the same dimensions, a 24-bit BMP is three times an 8-bit one. The result line shows the BMP's bit depth; if a 32-bit BMP has transparent areas, converting to PNG keeps them, while JPG puts them on white.

What is the difference between BMP and JPG?

BMP stores pixels without compression: there is no quality loss, but files are very large. JPG compresses the image lossily: it drops detail the eye hardly notices and brings the file down to a tenth or a twentieth. For sharing photos and screenshots JPG is enough; for images with crisp text and lines, or when pixels must stay exactly the same, choose PNG, which is lossless too but far smaller than BMP. Keeping images as BMP has no practical benefit today.

Why BMP files are so large and how much they shrink

A BMP writes pixels as they are: a 24-bit BMP is roughly width × height × 3 bytes, whatever the content, so a blank white page takes as much space as a photo. JPG and PNG compress the content, which is why converting from BMP saves far more than other image conversions. Flat-color screenshots and documents can shrink by more than 90 percent even as PNG; photos shrink by a similar amount as JPG.

The catch: JPG is lossy and the loss cannot be undone. If you will edit the image later, or it contains small text, drawings or a QR code, choose PNG; JPG can leave slight blur and ghosting around sharp edges. Transparent areas of a 32-bit BMP become white in JPG. Rare BMP variants (OS/2 format, 16-bit, RLE-compressed) may not open in some browsers; the tool shows a clear message when that happens.

JPG or PNG?

Email attachments, WhatsApp, upload forms and website photos: JPG at quality 85–90. Screenshots, tables, scanned documents, logos or pixel art: PNG; text stays crisp and the file is still a small fraction of the BMP. If you are unsure, try both and compare the sizes in the result line; every run starts from the original BMP.

If the file must fit under a limit (for example 1 MB on an upload form) and is still too large, lower the JPG quality to 70 first; if that is not enough, shrink the dimensions with the image resizer. If several BMPs have to go out as one document, convert them to JPG and then combine them with the JPG to PDF tool.

Frequently asked questions

Does converting BMP to JPG lose quality?

A little, yes — JPG is lossy. At quality 90 the difference is not visible; below 70, sharp edges start to blur slightly. For zero loss, pick PNG as the output: the pixels stay identical and the file is still much smaller than the BMP.

Should I convert BMP to PNG or JPG?

JPG for photos; PNG for screenshots, documents, logos and images with text. JPG gives the smaller file; PNG is lossless and keeps sharp edges. If the image has transparent areas, PNG keeps them and JPG puts them on white.

Why does my BMP file not open?

Either the file is not really a BMP (another file with a renamed extension), or it is a rare BMP variant (OS/2, 16-bit, RLE-compressed) that some browsers cannot decode. Open it in Paint on Windows, save it again as BMP or directly as PNG, and try again.

Is my file uploaded anywhere?

No. The BMP never leaves your device; decoding it and writing the JPG or PNG happen inside your browser, and the page keeps working offline after it loads.