1Drop your BMP images into the box above, or pick them from your device — there is nothing to install and no account to create.
2Choose how hard to squeeze: a quality or bitrate target, and optionally smaller dimensions if size matters more to you than detail.
3Start the job and let the workers re-pack the file; your original is never modified in place.
4Compare the new size against the original, then download the compressed BMP file.
Compress BMP FAQ
Does the format of my file change how much I can save?
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Very much so. 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 determines both the headroom available and whether the saving costs you anything in fidelity.
Is there anything specific to BMP I should know before compressing?
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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. It is worth knowing before you overwrite an original you might need again.
How does Compress BMP actually make the file smaller?
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Concretely, every pixel stays bit-exact and the saving is won from a stronger DEFLATE or LZW pass plus palette reduction where the image genuinely has few colours, so a screenshot or a piece of line art shrinks far more than a photograph does. Nothing about it depends on you installing software: the job runs server-side and hands back a finished file.
How much smaller will my file get?
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That is decided by the content, not by the tool. Photographic detail and film grain resist compression; flat colour, text and silence collapse. A realistic expectation is a large reduction on anything with big uniform regions and a modest one on a busy photograph or a high-motion clip.
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 Compress 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 Compress 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 Compress 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 Compress 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. Compress BMP is on the same upload and the same account so those questions get answered in one place.
Once Compress 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.
