BMP to PDF Converter

Convert BMP to PDF Online

Bitmaps are awkward to send: they are large, they carry no page geometry, and plenty of mail clients and document systems will not preview a .bmp at all. Wrapping the image in a PDF fixes all three problems at once — the file becomes a page with a defined size that opens in any reader, on any operating system, without a plugin. Drop one bitmap in for a single-page document, or drop a folder's worth in and get one PDF with the images in order.

How to Convert BMP to PDF

1. Upload Your BMP Files: Drag your bitmaps onto the page or click "+ Add Files". Add as many as you like and reorder them before converting — the sequence on screen is the page order in the finished document.
2. Choose Single PDF or Individual PDFs: The Combine? control opens on Single PDF, which merges every uploaded bitmap into one multi-page document. Switch it to Individual PDFs to get one file per image instead.
3. Set Paper Size, Layout and Placement: Paper size opens on A4 and also offers Original, Letter, Legal, Tabloid, Ledger, A3, ISO B4, ISO B5, ARCH A and ARCH B. Page layout opens on Portrait. Image placement opens on Contained, which fits the whole picture inside the margins; Cover fills the page instead and crops the overflow. Image alignment opens on Center, and Margin opens on Narrow (0.5").
4. Convert and Download: Click Convert and save the PDF. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared or made public.

What the Default Settings Produce

With the defaults, a page is A4 portrait — 210 x 297 mm, which a PDF stores as roughly 595 x 842 points. Take half an inch (36 points) off each edge for the Narrow margin and the drawable area is about 523 x 770 points. A 16:9 bitmap placed in that box is limited by width, so it lands about 523 points wide and 294 points tall — roughly 184 x 104 mm — centred vertically with generous white space above and below. Switching Page layout to Landscape or Paper size to Original removes most of that empty space.

Paper Size Reference

Frequently Asked Questions

Will all my bitmaps end up in one PDF, or one PDF each?

One PDF, by default. Combine? opens on Single PDF, so every bitmap you upload becomes a page of the same document in the order they appear on screen. Reorder the thumbnails before you click Convert and the page order follows. If you would rather have separate files — for example when each scan is a different record — switch Combine? to Individual PDFs and you get one document per image, delivered together.

Why is there so much white space around my image?

Because A4 portrait is much taller than a typical widescreen bitmap, and Image placement opens on Contained, which never crops. With the Narrow margin the drawable box is roughly 523 x 770 points, and a 16:9 picture only reaches 523 x 294 points inside it. There are three ways to close the gap: set Paper size to Original so the page takes the image's own proportions, switch Page layout to Landscape, or switch Image placement to Cover so the picture fills the page and the overflowing edges are trimmed.

Does converting to PDF make the file smaller than the BMP?

Almost always, and often by a very large margin, because a bitmap is close to a worst-case container. An uncompressed 24-bit BMP stores three bytes per pixel with every row padded up to a 4-byte boundary — on our test bench a 1920 x 1080 example measures exactly 6,220,854 bytes, which is 1,080 rows of 5,760 bytes plus a 54-byte header. Inside a PDF the picture is stored with real compression applied. If the resulting document still needs to be smaller for an upload limit, run it through Compress PDF.

Can I scan several pages as BMP and turn them into one document?

Yes — that is the main reason this tool exists. Older flatbed scanner drivers and some Windows scanning utilities still default to writing uncompressed .bmp files, one per sheet, which is unusable as a document. Upload the whole set, leave Combine? on Single PDF, check the order, and you get a single paginated file. For mixed sources — some pages as BMP, some as JPG or PNG — use Merge Image to PDF, which accepts several image formats in the same job.

What happens to a 32-bit bitmap that has transparency?

Image Transparency opens on Unchanged, so an alpha mask described by a BITMAPV4HEADER or BITMAPV5HEADER is carried through as-is rather than being pre-flattened. Set it to Removed if you would rather have the transparent regions filled before the picture is placed — worth doing when a downstream printer or document system renders unexpected alpha badly. Most .bmp files use the plain 40-byte BITMAPINFOHEADER and are fully opaque, in which case the setting makes no difference.

Will the text in a scanned bitmap be searchable in the PDF?

No. This conversion places your picture on a page; it does not read the picture. The words stay pixels, so Ctrl+F finds nothing and a screen reader has nothing to announce. Making the text selectable requires optical character recognition, which is a separate step in a dedicated OCR tool. If the source document exists as real text somewhere, exporting a PDF from that original will always beat scanning and converting.

Which paper size should I pick if I plan to print?

Match the paper the printer will actually load: A4 across most of the world, Letter in the US and Canada. Choosing the wrong one is the usual cause of a "scale to fit" prompt and a slightly shrunken print with uneven margins. If the output is only ever going to be viewed on a screen, Original is often the better choice — it gives the page the bitmap's own aspect ratio, so there is no letterboxing at all.

Is PDF the right target, or should I convert to an image format?

PDF is right when the file is a document — something to send, print, sign, archive or paginate. It is the wrong target when you just want a smaller picture for a web page or a message, because a reader has to open it before anything is visible. For that, convert to an image instead: BMP to PNG keeps every pixel, BMP to JPG is the smallest widely-supported photographic option, and BMP to WebP is the smallest of the three for the modern web.

Can I get the bitmap back out of the PDF afterwards?

You can extract an image, but it will not be a byte-identical bitmap. PDF to BMP renders the page back to a raster, which means the result depends on the render resolution and on whatever compression was applied when the picture was placed. Keep the original .bmp — or a lossless copy — if you may need the exact source pixels again.