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Convert BMP to PDF

Scanners and till systems still write bitmaps. Turn them into one PDF you can email or file, in your browser.

Drop files here or click to browse. BMP / DIB / JPG / JPEG / PNG accepted, batches welcome

Drop bitmaps above, get one PDF back, each page sized to its image.

Bitmaps are what old equipment produces. Flatbed scanners, fax software, till systems and a good deal of laboratory and industrial kit still write .bmp and nothing else. The file then has to go somewhere that expects a document: a claim, a return, an accountant, a printer.

One page per image, in the order they arrive. Number the filenames when the sequence matters, since a scanner's own numbering is not always the order you want.

The images are redrawn on the way in. Each bitmap is re-encoded as a high-quality JPEG before it becomes a page. For scanned text and receipts the difference is invisible. For anything where every pixel counts, BMP to PNG keeps the original exactly and skips the document step.

Size: the PDF is far smaller than the bitmaps that went into it. A 1920 by 1080 bitmap occupies about 6MB whatever it holds, and the same page inside the PDF is usually a few hundred kilobytes.

A bitmap almost always arrives uncompressed, and the PDF that comes out is routinely a fraction of the size of the files that went in.

Frequently asked questions

Does the image lose quality?

A little. Each bitmap is re-encoded as a high-quality JPEG on the way in. On scanned text, receipts and forms you will not see it.

What page size does it use?

Each page is sized to its own image. Nothing is cropped and no white margin appears around a page that was never A4.

Can I mix bitmaps with JPGs and PNGs?

Yes. Drop them together and each becomes a page in the order they arrive.

Why is the PDF so much smaller than my bitmaps?

Because bitmaps store every pixel uncompressed, at roughly 3 bytes each, while the PDF holds a compressed copy. A folder of 6MB scans routinely becomes a document of a few hundred kilobytes per page.

What happened to the transparency in my bitmap?

It is flattened onto white. PDF pages have no transparency behind them, and an alpha channel with nothing underneath would otherwise come out black.