Updated · Built and checked by the PlinzoTools team, formulas tested against published sources
Convert a JPG image to BMP instantly, right in your browser.
Upload a JPG file to convert it to BMP.
This tool converts a JPEG image to Windows Bitmap entirely in your browser -- the file is decoded, redrawn onto a canvas, and re-encoded as a real, uncompressed BMP without ever being uploaded to a server. BMP has no browser-native encoder (unlike JPG/PNG/WebP), so this uses a hand-rolled BMP encoder built specifically for this site rather than any external conversion service.
Click the upload area and choose a JPG file. The converted preview appears immediately; click Download to save it as a real .bmp file.
Need to go the other way? Use the BMP to JPG tab above, or open the BMP to JPG converter directly.
BMP is mostly needed today for compatibility with older Windows software, certain scanning/printing tools, or legacy enterprise systems that specifically require it -- it's rarely the right choice for a new file if you have any other option, since it's uncompressed and produces files several times larger than an equivalent PNG, JPG, or WebP.
The BMP this tool writes is a 24-bit, uncompressed file: a 14-byte file header, a 40-byte info header, and then three bytes (blue, green, red) for every pixel. Each row is padded so its length is a multiple of four bytes. That makes the size predictable before you even convert.
File size = 54 bytes + (width x 3 rounded up to a multiple of 4) x height
As a hypothetical example, a 1000 by 800 pixel image has a row of 3000 bytes (already a multiple of four), so the file is 54 + 3000 x 800 = 2,400,054 bytes, roughly 2.3 MB. That figure is the same no matter what the picture looks like, because there is no compression. A 300 KB JPG can therefore become a BMP several times larger, and a very large photo can easily reach tens of megabytes. The size badge in the tool shows the real output size for your file.
A JPG has already been through lossy compression, so the pixels your browser decodes are the final version of the picture. The BMP records those decoded pixels exactly, which means the BMP looks identical to the JPG on screen. It will not gain sharpness, remove compression artifacts, or bring back detail that was discarded earlier. Since JPG has no transparency, there is no alpha channel to worry about in this direction, and no background handling is needed.
Some older scanning workflows, industrial imaging viewers, embedded displays, and legacy Windows applications only accept BMP input. If you have a folder of JPG photos to hand over to such a system, convert one and test it in the target software before converting the rest, so you can catch any size or color depth requirements early.
No -- the whole conversion, including the BMP encoding itself, happens locally in your browser. Your file never leaves your device.
No -- converting a JPEG (which has already discarded some image data through lossy compression) to BMP doesn't recover that lost detail. It only changes the container format.
No. It will look the same, because the tool records the decoded JPG pixels. Existing compression artifacts remain.
Multiply width by height by three, round each row up to a multiple of four bytes, and add 54 bytes. The tool also shows the exact output size after conversion.
Yes. The tool writes uncompressed 24-bit true color BMP files, not palette-based ones.
No. Only pixel data is written, so metadata such as camera model or location is not included in the BMP.
JPG (JPEG) and BMP aren't interchangeable: JPG (JPEG) works well for photographs and images with smooth colour gradients, whereas BMP is the better fit for legacy Windows software and pipelines that need raw, uncompressed pixels.
| JPG (JPEG) | BMP | |
|---|---|---|
| File extension | .jpg | .bmp |
| Compression | lossy | usually none (uncompressed) |
| Transparency | No transparency | No transparency |
| Animation | Single image | Single image |
| Colours | 16.7 million (24-bit) | 16.7 million (24-bit as written here) |
| Best for | photographs and images with smooth colour gradients | legacy Windows software and pipelines that need raw, uncompressed pixels |
| Support | every browser, phone, camera and editor | Windows and most editors; browsers open it but it is rarely used on the web |
The conversion happens in your browser; the file is never uploaded.