1Upload your BMP images and wait for the preview to appear.
2Pick a crop preset: 1:1, 16:9 or 4:3 cuts the largest centred area of that shape, and Free Crop keeps the whole picture.
3Start the crop and wait for the result.
4Download the cropped BMP file, with everything outside the frame discarded.
Crop BMP FAQ
Does my source format change how a crop behaves?
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It can. BMP is essentially raw uncompressed RGB rows with a small header, so it is perfectly lossless and enormous — often 10-20x the size of the same image as PNG. That decides whether the crop is a pure pixel operation or whether the file has to be rebuilt around it.
Anything specific to BMP worth knowing before I crop?
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Yes — because nothing is compressed, a BMP is fast to read and edit but punishing to upload, and it carries no metadata to preserve. That is the sort of detail that only shows up after you have overwritten the original.
What is the most common mistake when cropping BMP images?
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Cropping before resizing. Crop first from the full-resolution original, then resize the result — doing it the other way round means the region you keep has already lost detail it did not need to lose.
Can I crop several files to the same region at once?
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Several files in one job need a paid plan. Free use is one file per conversion, one conversion an hour. On a paid plan you can add several files to one job, then download each result on its own or all of them in one ZIP.
Can I run Crop BMP on several BMP images at once?
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Yes — upload the set and they process in parallel under one set of settings. Lossless files are larger, so a big batch is bound by your upload speed rather than by the processing itself.
Does the alpha channel survive?
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Yes. PNG and TIFF carry a full 8-bit alpha channel and it is preserved end to end. It is only flattened if you deliberately target a format that has no alpha, in which case transparent pixels are composited onto white.
Does Crop BMP cost anything?
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No. Crop BMP is free without an account and adds no watermark. The upload and the result are deleted automatically about 24 hours after the job, which leaves time to download the result.
Is there a file size limit on Crop BMP?
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Yes: free accounts process images up to 5 MB each; lossless sources hit that ceiling sooner than photographs do, because nothing has been thrown away yet. If you are over it, converting to PNG first is often enough on its own — a BMP is routinely ten to twenty times the size of the identical image as PNG.
Why does a PNG site host Crop BMP?
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PNG.to is built around the format you use when you cannot afford to lose a pixel: lossless, alpha-capable, and the correct answer for screenshots, logos, line art and anything with hard edges. Image work is rarely one step: people arrive to change a format and leave needing the picture a different size, a different weight or a different shape. Running Crop BMP on the same upload pipeline, the same size caps and the same account is the whole reason it is here rather than on a fourth tab.
What should I do with the result once Crop BMP is finished?
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The converter on this site moves images to and from PNG, JPG, WebP, GIF and SVG — which is the step where the decision about transparency actually gets made. That is the step most people actually came for, and doing it after Crop BMP rather than before it means the conversion works from the file you finally settled on.
Is Crop BMP here the same tool the sibling sites run?
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The engines are shared — the same libraries, the same workers, the same limits. What differs is the advice, and the advice here starts from one fact about the format this site is named after: there is no quality slider to get wrong — a PNG round-trips bit-exactly, so the only thing edits cost you is file size. A PNG site is opinionated about where PNG is the right destination and where it is not, and that judgement is worth more than the button.
Do I need an account, and does anything get kept?
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No account is needed. Uploads and results are kept for about 24 hours, which leaves time to download the result, and are then deleted automatically; nobody reads, lists or indexes them. Several files in one job need a paid plan.
