BMP to PDF
Convert BMP bitmap images to one PDF, one page per image, with the pixels stored losslessly.
Tool workspace
Nothing is uploaded. Files are read in this tab and stay on your machine.
Convert BMP images to PDF
Save your download before you leave the page — it exists only in this tab.
How do I convert BMP files to PDF?
Select up to 500 BMP files, each up to 64 MiB. One page is produced per image, in the order listed.
Choose whether each page takes the image's own size or fits a fixed sheet.
Select Create PDF and save the result before leaving the page.
Why is a BMP always converted before it goes into a PDF?
Convert BMP bitmap images to PDF, combining one or more into a single PDF with a page per image. BMP stores its rows in a form a PDF cannot use, so your browser decodes each image and it is stored losslessly.
A BMP holds uncompressed rows, stored bottom row first with padding at the end of each row, which is not how a PDF stores an image, so your browser always decodes a BMP and its pixels are written into the PDF with lossless compression. Any resolution the BMP records is not used. The file signature, its declared width and height and its pixel count are checked from the header first, so an impossible file is refused before any decoding starts. Where the browser reads transparency from a 32-bit BMP, that transparency is kept.
How Xenmark makes it easy to convert BMP files to PDF
Bitmaps stored losslessly and compressed
Each BMP is decoded by your browser, and its pixels are written into the PDF with lossless Flate compression rather than as raw uncompressed rows.
Nothing leaves your machine
Nothing is uploaded. Files are read in this tab and processed in memory, with no account and no server for them to go to.
Impossible headers are refused early
The signature, width, height and pixel count are read from the BMP header first, so a file declaring an impossible size is refused before any decoding starts.
Decoded size must match the header
If the browser decodes a bitmap to different dimensions from the ones its header declares, the file is refused rather than placed on a wrongly sized page.
Grey bitmaps kept to one channel
A bitmap whose every pixel is an opaque shade of grey is stored as a single grey channel instead of three, which keeps the resulting PDF smaller.
Nothing to install
It runs in the browser you already have. There is no plug-in, no desktop application and no sign-up to get through first.
Limitations
What this tool does not do, stated up front.
Every BMP is decoded and rebuilt; there is no untouched path, because the two formats store rows differently.
Any resolution stored in a BMP is not used, so each page is sized from the density you choose or fitted to the sheet you pick.
Your browser does the decoding, so a BMP it cannot read is refused with a message rather than converted in part.
Questions
Does converting BMP to PDF lose quality?
No. Your browser decodes the bitmap and its pixels are stored with lossless compression, so the image in the PDF matches the decoded bitmap pixel for pixel.
What size will the pages be?
Each page is sized from the density you set, because a resolution stored in the BMP is not used, or from the sheet you choose if you fit to a fixed size.
Are very large BMP files accepted?
Yes, up to 64 MiB per file and 40 million pixels per image. The pixel count is read from the file header before decoding, and a larger image is refused.
Why did Xenmark build a free BMP-to-PDF converter?
Xenmark AS is a Norwegian software company building browser-based drawing review tools for owners, consultants, operators and other teams that receive and review technical drawings. Those teams handle PDFs every day, and not every file should be sent to a website just to merge, split or check it — a tender document, a client’s drawing set, a revision that is not released yet. So these everyday tools are free and run entirely in your browser: no account, no upload step, and no server ever receives the file. You can check that yourself — open your browser’s network tab, convert a bitmap, and watch nothing leave. What this tool cannot do is listed under Limitations above.
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