BMP to JPG Converter - Dramatic Size Reduction, No Upload

Browser-local tool

Use BMP to JPG

Your image is decoded and re-encoded on this device. No upload request is made.

Choose BMPSelect a BMP file from this device

Output formatBackground for transparency

Quality 92%

JPG cannot store transparency. Transparent pixels will use #ffffff.

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About BMP to JPG

A BMP file stores every pixel at full size with essentially no compression, which makes it the largest common image format by a wide margin. A photograph that occupies two megabytes as a JPEG can easily take thirty as a BMP, holding exactly the same picture. That is why BMPs turn up as a problem rather than a choice: something old produced one, and now it will not attach to an email or upload to a form. Converting to JPEG typically cuts the size by ninety per cent or more with no visible difference on photographic content, because almost all of what BMP was storing was redundant. This is the rare conversion where the size reduction is dramatic and the quality cost is close to invisible.

Shape and export choices

The BMP is decoded by the browser, which handles the common bit depths including the 24-bit and 32-bit variants.
A canvas is created at the original dimensions and filled with white, since a 32-bit BMP can carry an alpha channel that JPEG cannot represent.
The image is encoded as JPEG at a high quality setting, which is where the size reduction comes from.
No resizing is applied. The pixel dimensions are identical; only the storage changes.
The before and after sizes are displayed, and the difference is usually large enough to be worth seeing.

Good fits for BMP to JPG

A BMP too large to email

This is the usual reason people arrive. The JPEG is typically a small fraction of the size with no visible difference in a photograph.

Output from older scanning or industrial software

Such tools often write BMP by default. Converting for storage saves a great deal of space across a batch.

Check the image before download

JPEG is lossy. The first compression of a previously uncompressed image is usually invisible on photographs, but it is real and permanent.
Screenshots and diagrams are the weak case. Sharp text against flat colour picks up visible artifacts, so those belong in PNG.
Any transparency in a 32-bit BMP is flattened to white, since JPEG has no alpha channel.
Very old BMP variants using RLE compression or unusual bit depths may not decode in a browser.
The original BMP is not improved by this. If you need to keep an exact copy, keep the BMP as well.

Questions about BMP to JPG

Why are BMP files so large?

Because BMP stores each pixel individually with no compression. A three-megapixel image needs roughly nine megabytes regardless of content.

How much smaller will the JPEG be?

Frequently ninety per cent or more for photographs. Both sizes are shown so you can see the actual figure.

Will I notice the quality loss?

Rarely on a photograph. On a screenshot or a diagram you may, and PNG is the better destination for those.

Does transparency survive?

No. A 32-bit BMP with alpha is flattened onto white, because JPEG has no transparency.

BMP to JPG