BMP to PDF Converter
Convert BMP to PDF in your browser. BMP files usually come from Windows Paint, legacy Windows programs, embedded displays and some scanners; PDF is the better fit for sharing, printing and submitting documents. You get a one-page PDF with the image embedded as a JPEG. Nothing is uploaded.
- Processed locally
- No upload, no wait
- No sign-up
- No watermark
Drop images here
or choose files · paste with Ctrl/⌘ V
BMP expected · other image formats also work
How to use BMP to PDF
- 1
Add your BMP files: drop them here, choose them, or paste from the clipboard.
- 2
Pick the colour that replaces transparent areas, since PDF has none.
- 3
Click Convert. Each file is decoded and encoded in a background thread on this device.
- 4
Download the .pdf files one at a time or together as a ZIP.
Why use Aback Images for bmp to pdf
Where the PDF goes next
PDF opens in every browser, operating system and office suite.
PDF next to BMP
A lossy PDF usually comes out far smaller than the BMP, which stores usually none; RLE for some 4 and 8-bit files.
The first lossy pass
The BMP holds 1, 4, 8, 16, 24 or 32 bits per pixel with nothing discarded yet. This conversion is the first lossy encode these pixels see, and hard edges and flat colour show it first.
Processed on your device
Your images are decoded, edited and encoded inside this browser tab by Web Workers. Nothing is uploaded to a server.
BMP vs PDF
What changes from BMP to PDF
Encoding: the BMP uses usually none; RLE for some 4 and 8-bit files; PDF uses per object: images inside are usually JPEG or Flate-compressed, and the download is a one-page PDF with the image embedded as a JPEG.
Bit depth: 1, 4, 8, 16, 24 or 32 bits per pixel in the BMP; PDF allows whatever the embedded images use, and the PDF written here has 8 bits per channel.
Colour: RGB or an indexed palette in the BMP; PDF supports RGB, CMYK, greyscale or spot colours, written here as 8-bit sRGB.
Transparency: the BMP stores it as an optional fourth byte in 32-bit files, which many programs ignore; the PDF has none, so transparent areas are filled with the colour you choose.
Metadata: the BMP can carry nothing beyond the header's resolution fields (and a colour profile in rare V5 headers); PDF can carry document info and XMP, but nothing is copied across.
About BMP
BMP stores raw, uncompressed pixels. Files are huge but trivially simple, which is why some legacy Windows software, embedded displays and printers still ask for it.
A BMP is a 14-byte file header ('BM' and the offset to the pixels), a DIB header (40 bytes, or 108 and 124 bytes in the V4 and V5 versions that add colour masks and alpha), an optional palette, then pixel rows padded to 4 bytes and normally stored bottom-up.
BMP files usually come from Windows Paint, legacy Windows programs, embedded displays and some scanners.
About PDF
PDF is the standard for documents that look identical everywhere. Images placed in a PDF can be printed, emailed and combined into multi-page documents.
When converting BMP to PDF makes sense
PDF is the better choice for sharing, printing and submitting documents, while BMP suits legacy software and embedded systems that require it.
PDF strengths: Opens identically on every device; Multiple pages in one file; Print-ready page sizes. Drawbacks to weigh: Not an image format: harder to edit or embed.
Limitations
- BMP stores nearly every pixel literally, so almost any compressed target is several times smaller.
- A 32-bit BMP can carry an alpha byte that most programs ignore; if the image suddenly gains transparent areas after converting, that byte was set.
- The page matches the image size unless you choose a paper size, and the image is embedded as a JPEG.
- To put several images into one multi-page PDF, use Image to PDF.
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Frequently asked questions
Does converting BMP to PDF lose quality?
PDF is lossy, so detail the eye barely notices is discarded to save space.
What happens to transparency when converting BMP to PDF?
BMP stores transparency as an optional fourth byte in 32-bit files, which many programs ignore. PDF has no alpha channel, so transparent pixels are composited onto a solid colour, white unless you pick another. To keep transparency, convert to PNG, WebP or AVIF instead.
Can I put several images in one PDF?
This converter creates one PDF per image. To combine many images into one multi-page PDF with page size and margins, use Image to PDF.
Which apps open PDF files?
Every browser, operating system and office suite.
Are my images uploaded anywhere?
No. Processing happens inside your browser with WebAssembly and Web Workers. The site only downloads the app code and codecs; your files never leave your device. You can confirm this with the live upload counter on the tool, or in your browser's network panel.
Can I process many files at once?
Yes. Drop a whole selection or folder. Files are processed in parallel on several worker threads, each result can be downloaded on its own, and everything can be saved as one ZIP.
Is it free? Is there a file limit or watermark?
It is free with no account, no watermark and no daily limit. The only limit is your device's memory: very large images (over roughly 100 megapixels) may be refused to keep the tab from crashing.