1Upload your BMP images and wait for the preview to appear.
2Drag out the region you want to keep, or lock the selection to 1:1, 4:3 or 16:9 and drag freely inside that ratio.
3Confirm the crop — the same rectangle is applied to every file you uploaded, which is how a set ends up genuinely consistent.
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.
How does Crop BMP select and cut the area?
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Concretely, the pixel rectangle you select is written straight out again with no re-encoding step at all, so a crop of a lossless image is exactly the corresponding region of the original, byte for byte. You drag the region you want directly on the preview, or type exact pixel coordinates if you already know them.
Can I crop to a fixed aspect ratio?
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Yes. Lock the selection to 1:1, 4:3, 16:9 or any custom ratio and drag freely inside that constraint — which is how you get a set of images that all fit the same layout slot without measuring anything.
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.
What can I upload to Crop BMP?
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PNG, BMP and TIFF are the lossless raster formats this handles directly, and lossy sources (JPG, WebP, GIF) work too if you want them in the same batch. Multi-page TIFFs are detected and handled page by page.
Is there a file size limit on Crop BMP?
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Yes: free accounts process images up to 25 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.
Will Crop BMP lower the quality of my BMP images?
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No. A lossless source round-trips bit-exactly, so unless you explicitly ask for a lossy output format the pixels that come back are the pixels that went in. That is the whole reason to keep working in this family while you are still editing.
Why would a modern-format site run Crop BMP?
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WEBP.to is built around the modern replacement for both of the old defaults: one format that does lossy, lossless, alpha and animation, and reliably lands smaller than the JPEG or PNG it came from. People arrive here having decided the old defaults are costing them bandwidth, and that decision immediately raises the rest: what size, what quality, what happens to the transparency. Crop BMP is on the same upload and the same account so those questions get answered in one place.
Once Crop BMP has run, what is worth doing next?
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The converter on this site moves images to and from WebP, PNG, JPG and AVIF, which is where you decide whether a smaller file is worth losing the older browsers. Doing it in that order matters: pick the pixels first and the container afterwards, because the container is the cheap decision and the pixels are the expensive one.
Do the sibling sites run something different?
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The engines are identical — same libraries, same workers, same caps. What is different is the opinion attached, and the opinion here rests on a property of the format this site is named after: the same .webp extension can hold a lossy VP8 frame, a lossless one, or an animation, so the sensible processing path is decided per file rather than per extension.
What happens to my file, and is an account required?
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No account, and nothing is retained: uploads are deleted from the workers shortly after the job finishes, and nothing is inspected, listed or indexed. Accounts exist for history and batch size only.
