BMP to JPG Converter

Convert BMP to JPG Online

A Windows bitmap has no compression to speak of: the file is a header, an optional colour table, and then every pixel written out one row at a time. That makes BMP a fine hand-off format between Windows tools and a terrible one for email, web pages and upload forms, where a single screenshot can arrive as a multi-megabyte file. Converting to JPG re-encodes the same picture with lossy compression and usually drops it by an order of magnitude or more, with no visible change at high quality settings.

How to Convert BMP to JPG

1. Upload Your BMP File: Drag your bitmaps onto the page or click "+ Add Files" to browse. Several files can be queued and converted in one pass with identical settings.
2. Pick a Quality Preset: Under Image Compression, the Quality Preset dropdown starts on "Very High (Recommended)". Drop it to High or Medium when the size matters more than the last few percent of fine detail.
3. Cap the Size or Rescale (Optional): Switch Image Compression to Specific file size to aim at an exact figure in bytes, kilobytes or megabytes, or use Image resolution — preselected on "Keep original" — to scale the pixel dimensions down instead. File extension controls whether the download is named .jpg or .jpeg.
4. Convert and Download: Click "Convert" and save the JPG. No sign-up, no watermark. Files are uploaded over an encrypted connection, converted on our servers, and deleted automatically after a few hours.

Why the BMP Was So Big in the First Place

A bitmap's size is arithmetic, not content. Each pixel row occupies width x bytes-per-pixel, rounded up to the next 4-byte boundary, and the file holds every row in full — so a photograph of a busy street and a picture of a blank wall at the same dimensions weigh exactly the same. Those are the numbers a JPG conversion is starting from:

JPG works the other way round: it discards perceptually redundant detail, so the output size follows how complex the picture actually is. Flat screenshots and simple graphics collapse enormously; dense, noisy photographs compress less. That is why nobody can promise a fixed ratio — but the direction of travel is never in doubt.

BMP vs JPG: What Actually Changes

JPG or JPEG — Which Extension Should You Pick?

They are the same format. The three-letter spelling exists only because early DOS and Windows filesystems limited extensions to three characters, and it stuck. This page exposes a File extension control with exactly two entries, JPG and JPEG, so you can match whatever the receiving system expects; the bytes inside the file are identical either way. Pick .jpg unless a specific tool insists on the longer spelling.

Frequently Asked Questions

How much smaller will my BMP get as a JPG?

Large enough that the comparison is usually made in multiples, not percentages. The bitmap side is fixed — a 1920x1080 24-bit BMP always holds 6,220,800 bytes of pixel data — while the JPG side depends on what is in the picture. Screenshots with flat UI panels shrink hardest; fine-grained photographic texture shrinks least. If you need a guaranteed ceiling rather than an estimate, use Specific file size and name the number you have to hit.

Will converting to JPG visibly lower the quality?

At the "Very High" preset it is hard to spot on photographic content. The exception is hard-edged material — text, UI screenshots, line art, flat colour with sharp boundaries — where lossy compression can leave faint halos around edges. That is a property of the format rather than this converter, and the fix is either to keep the preset high or to choose a lossless target such as BMP to PNG, which is still far smaller than the original bitmap.

Does JPG keep the transparency from my bitmap?

There is almost never any to keep. Alpha only exists in the later BMP header variants, and bitmaps written by Windows tools are opaque, so the question is usually moot. What is certain is the destination: JPG has no alpha channel at all, so anything transparent has to be composited onto a solid colour on the way in. If transparency genuinely matters, PNG is the target you want.

Why is my JPG larger than I expected?

Two common causes. The first is content — noise, film grain, foliage and fabric textures are expensive to encode, so a busy photograph resists compression in a way a screenshot does not. The second is the quality setting: "Highest" spends a lot of bits protecting detail nobody will see on screen. Stepping the Quality Preset down one notch usually cuts the file substantially with no visible change.

Can I convert a whole folder of bitmaps at once?

Yes. Queue them together and they convert with the same Quality Preset and Image resolution settings, then download individually. Batch conversion matters more for BMP than for most formats, because bitmaps are typically generated in bulk by screen-capture utilities, scanner software and older Windows applications — and it is those piles of near-identical multi-megabyte files that gain the most.

Should I keep the original BMP after converting?

Keep it if the image is a master you will edit again. JPG loss is cumulative: every save re-encodes, and detail lost at one stage never comes back at the next. For a finished picture that is only ever going to be viewed or shared, the BMP is dead weight and the JPG is the version worth keeping. If you later need the bitmap back for a Windows tool, JPG to BMP rebuilds one, though it cannot restore what the JPG encoder already discarded.

What is the difference between compressing a BMP and converting it to JPG?

Compressing a BMP means keeping the format and losing very little — bitmaps only support run-length coding of palette images, so there is not much room to work with. Converting to JPG changes the compression model entirely, which is where the real savings live. If you specifically need the output to stay a bitmap, compress BMP is the tool for that; if you already have JPGs that are too big, compress JPEG re-encodes them without changing format.

Is my file private, and how long do you keep it?

Your bitmap is uploaded over an encrypted connection, converted on our servers, and deleted automatically after a few hours. There is no sign-up, no watermark on the output, and files are never shared or made public. Because uncompressed bitmaps are heavy, upload time is usually the longest part of the job — the encode itself finishes quickly once the file has landed.