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Convert To PDF

BMP to PDF

Convert supported Windows .bmp files to PDF, with variant limits stated up front.

Processed locally in your browser. Your file is not uploaded to any server. How this works

  1. 01Add your files
  2. 02BMP to PDF
  3. 03Download

Runs in your browser · nothing uploaded

About BMP to PDF

BMP includes several incompatible variants, so this tool accepts a specific subset: a Windows BITMAPINFOHEADER with a 40-byte DIB header, one plane, uncompressed BI_RGB data (compression value 0), and 24-bit or 32-bit pixels. Bottom-up and negative-height top-down rows are supported. Header bounds, pixel offsets, row padding and available pixel data are checked before browser decoding. PDF cannot carry BMP directly: the browser decodes the bitmap, draws it onto a white background and encodes lossless PNG for embedding. The PNG step adds no lossy compression, but any decoded transparency is flattened onto white rather than preserved. Images must be no larger than 8192 pixels per side and 32 million pixels total; oversized inputs are refused, not downscaled. Conversion also requires native image decoding and canvas support. Output size depends on the image and PDF overhead, so a smaller file is not guaranteed.

How to BMP to PDF

  1. 01

    Add supported .bmp files

    Use uncompressed 24-bit or 32-bit Windows BMPs with a 40-byte DIB header and one plane. Top-down rows are supported; other variants should be re-exported as PNG.

  2. 02

    Set the page geometry

    Auto uses the bitmap’s pixel dimensions as PDF points, plus your margins; choose A4 or Letter for fixed paper dimensions.

  3. 03

    Convert and save

    Press Convert to PDF. Review warnings for skipped files, then download the successful pages. Decoded pixels are embedded through lossless PNG on white.

What this tool does

  • Lossless PNG encoding after native decoding and compositing onto white
  • Validates header bounds, pixel data and dimensions before decoding
  • Supports 40-byte Windows DIB, one-plane, BI_RGB 24-bit and 32-bit BMPs, including top-down rows
  • Auto or fixed page sizing with a point-precise margin
  • Runs locally, so multi-megabyte bitmaps never need uploading

Limitations worth knowing

Every PDF tool has constraints. Stating them plainly is more useful than discovering them halfway through your work.

  • PDF cannot carry BMP data natively, so each bitmap is decoded by the browser’s image decoder and re-encoded before embedding rather than copied verbatim.
  • Only 40-byte Windows BITMAPINFOHEADER, one-plane, BI_RGB compression 0 with 24-bit or 32-bit pixels is accepted. RLE, bitfields, indexed palettes, OS/2 and other DIB headers are refused; re-export as PNG.
  • Native browser image decoding and canvas encoding are required. Inputs above 8192 pixels per side or 32 million pixels total are refused rather than resized; large batches can still consume substantial memory.
  • Decoded transparency is flattened onto white. The PNG encoding is lossless from that composited image onward, and a smaller PDF is not guaranteed.

How your file is handled

This tool runs entirely inside this browser tab. When you choose a file, your browser reads it from your own disk and hands the bytes to JavaScript running on this page — no network request carries your document anywhere. You can confirm that yourself: open your browser’s developer tools, switch to the Network panel, and run the tool. You will see no upload.

Nothing is stored after the fact. Closing or reloading this tab discards the file, the result and everything derived from them, because none of it ever left your machine. Read how local processing works.

Questions about BMP to PDF

Will the PDF be smaller than my BMP files?

It may be, but there is no size guarantee. Supported BMPs store uncompressed pixels, while the white-background PNG used for embedding is compressed losslessly. The final size depends on image content, dimensions and PDF overhead.

Is any quality lost converting BMP to PDF?

There is no added lossy compression. The browser decodes the BMP and composites it onto white, then the resulting pixels are encoded as lossless PNG for embedding. This is not a byte-for-byte BMP copy, and decoded transparency is not retained.

My BMP won’t open here. Why?

Check the error. The accepted subset is a 40-byte Windows BITMAPINFOHEADER, one plane, BI_RGB compression 0, and 24-bit or 32-bit pixels, including top-down rows. Other variants and malformed pixel data are refused. Images above 8192 pixels per side or 32 million pixels total must be resized. Native browser decoding and canvas support are also required; re-exporting as PNG may avoid a variant or decoder limitation.

Can I combine several bitmaps into one multi-page PDF?

Yes. Add supported bitmaps and arrange their order. Each successfully decoded image becomes a page; failed inputs are skipped with warnings when others succeed. If none can be converted, the run reports an error instead of creating an empty PDF.

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