Picture Batch BMP to JPG
BMP to JPG
A bitmap has no compression at all, so this conversion is where the dramatic size reductions live — 20 or 30 times smaller is ordinary for a photographic image. It is also lossy, which for a photograph is a fair trade and for a screenshot full of text is not.
Drop BMP images here
BMP files — or any of PNG, JPEG, WebP, AVIF, ICO, TIFF, GIF or camera raw (CR2, CR3, NEF, ARW, DNG, RAF, ORF, RW2). Everything runs on this device.
Your images never leave this device. They are decoded and re-encoded by your own browser, and the security policy on every page blocks this site from sending them anywhere.
Lossy, no transparency, opens absolutely everywhere, small for photographs.
The standard range for photographs. Hard to distinguish from the original.
Images keep their original dimensions.
JPEG cannot store transparency. Nothing in the queue currently has transparent pixels, so this has no effect yet.
Exif is carried across where both formats can hold it. Nothing currently in the queue has any.
BMP metadata cannot be read by this tool, so there is nothing to carry across. Orientation is still applied to the pixels.
What happens to your image
Expect a much smaller file than a lossless source, at the cost of some detail.
| Property | Outcome |
|---|---|
| Transparency | Not preserved: Lost. JPEG cannot store it, so transparent areas are filled with a background colour you choose. This cannot be undone in the output. |
| Image quality | Partly preserved: JPEG is lossy: the image is re-compressed and detail is discarded to make the file smaller. The quality control decides how much. |
| Colour | Partly preserved: Converted to sRGB. Decoding an image colour-manages it into the browser's own space, so the output is sRGB and is left untagged, which every viewer reads as sRGB. A wide-gamut source is reported before conversion. |
| Exif metadata | Not preserved: BMP metadata is not read by this tool, so there is nothing to carry across. |
| Orientation | Preserved: Applied to the pixels, and the tag is reset to upright afterwards so nothing rotates the image a second time. |
Is your bitmap a photograph or a screenshot?
The answer decides whether this is the right page. JPEG was designed for continuous-tone photographic images and does an excellent job on them. It was not designed for hard edges, and it handles them visibly badly: black text on white acquires a grey halo, thin lines get fuzzy, and flat areas of colour develop faint blocky patterns.
Bitmaps are very often screenshots or diagrams, because that is what old software saved. If yours is, use PNG instead — it is lossless, it has no ringing, and for flat-coloured images it is usually smaller than the JPEG would have been anyway.
Transparency is flattened, and you pick the colour
A 32-bit bitmap can carry transparency and JPEG cannot store any, so transparent areas have to become a solid colour. That colour is yours to choose rather than assumed to be white, and the result records what was used.
If something goes wrong
Text in the converted image looks blurry or has a halo.
JPEG ringing around hard edges — an inherent property of the format, not a setting.
What to do: Use PNG output. For text and line art it is both better looking and usually smaller.
The file is still large.
The quality is set high, or the image is very large in pixel terms.
What to do: Lower the quality, or use the resize control. A 4000-pixel-wide image displayed at 800 pixels is wasting most of its bytes.
Questions
How much smaller will the JPG be?
For a photographic bitmap at quality 85, typically 20 to 40 times smaller. A 36 MB bitmap of a 12-megapixel photo lands somewhere near 1 to 2 MB.
Should I use JPG or PNG for my bitmap?
Photographs: JPG. Screenshots, diagrams, logos, anything with text or flat colour: PNG, which will be both cleaner and often smaller.