Convert BMP to JPEG
Free online converter for BMP files. Universally supported lossy photo format. Nothing to install, no watermark, and every file is deleted automatically.
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Upload a BMP file to convert it to JPEG. Up to 3 files at once, 100 MB each.
Free · up to 3 files · 100 MB each · files deleted automatically after 1 hour.
About BMP and JPG
BMP .bmp
Microsoft's plain bitmap. It generally stores pixels with no compression at all, which makes it simple to read and very large on disk.
Good for
- Dead simple — every pixel stored literally
- No compression artefacts of any kind
- Reliably readable by old Windows software
Trade-offs
- Enormous files, often ten times a PNG of the same image
- Effectively unusable on the web
- Transparency support is inconsistent between readers
image/bmp
JPEG .jpg
The photographic standard since 1992. JPEG throws away detail your eye is least likely to miss, which is why a photograph saved as JPEG is a fraction of the size of the same image saved losslessly.
Good for
- Opens everywhere — no format is more widely supported
- Very small files for photographs and other continuous-tone images
- A quality dial, so you choose the trade against file size
Trade-offs
- Lossy: detail is discarded permanently, and re-saving repeatedly compounds it
- No transparency at all
- Sharp edges, flat colour and text pick up visible halos
image/jpeg
BMP and JPG side by side
| BMP | JPG | |
|---|---|---|
| Compression | Uncompressed | Lossy |
| Transparency | Limited — 32-bit variants only | No |
| Animation | No | No |
| Typically used for | Legacy Windows software, intermediate working files | Photographs, camera output, web images |
What changes when you convert BMP to JPG
Transparency is flattened
BMP carries an alpha channel and JPG has none, so anything transparent has to become a solid colour. We composite onto white. If the image was designed to sit over a coloured background, convert to a format that keeps alpha instead — or expect a white box around it.
How the JPG is written
Our default is quality 82 through mozjpeg, written progressively so it renders in passes over a slow connection. The quality control on the converter moves this if you need to — the default aims to be indistinguishable from the source at a sensible file size, rather than to win a compression benchmark.
Colour detail is stored at half resolution
JPG keeps full brightness detail but records colour at half resolution in each direction, because the eye is far more sensitive to the first than the second. On photographs it is invisible. On saturated edges it is not: red text on white, thin coloured lines and flat graphic shapes can pick up fringing. If the BMP is a screenshot, a logo or anything with text in it, a lossless format will treat it far better.
Expect a dramatic drop in size
A BMP stores every pixel literally, with no compression at all — which is why they are so large. JPG compresses, so the same image commonly lands somewhere between a tenth and a half of the size it started at. Nothing about the picture changes to achieve that: the file was simply storing its pixels in the least efficient way available.
This step is irreversible
BMP holds every sample; JPG keeps a close approximation. The file gets dramatically smaller, and converting back later will not undo it. Keep the BMP original if it is a master you will work from again.
Other BMP conversions
Other ways to get JPEG
Worth reading next
Why your PNG is so much bigger than your JPEG
The same photograph can be 300 KB as a JPEG and 4 MB as a PNG. Here is what each format is actually doing, and how to tell which one your file wants to be.
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Where your transparent background went
Transparency is the property most often lost silently in a conversion — the file looks perfect until it lands on a coloured background and grows a white rectangle.
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