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Convert BMP to PDF free, without uploading
BMP to PDF shrank our 1281×1600 px test portrait from 5.87 MB to 254 KB (−96%). Quality stays high unless you set a KB limit. Drop the BMP (.bmp, .dib) on the tool below and download the PDF; nothing is uploaded.
BMP to PDF
PDF · no file-size limit · original pixel size · white background
No file-size limit is set: PixelFit saves at high quality and changes only the format and any pixel size you set.
Fit, background and padding white background · page the size of the picture
Saving presets is part of Pro.
The result appears here: the exact byte count, pixel size and quality, the size before and after, a preview and a download button.
The batch kit (one ZIP for up to 500 photos, several photos merged into one PDF) is part of Pro.
What changes from BMP to PDF
2 of these 3 points lose or alter something on the way from BMP to PDF; the rest carry over.
- Lost or changed: A PixelFit PDF page holds a JPEG, which is lossy: the exact pixels of the BMP are approximated, which is invisible on photos at high quality but can blur sharp text and edges.
- Lost or changed: Metadata is not carried over: the BMP's header resolution fields are dropped by the canvas.
- Kept: The PDF is a document with one page per image; the page size follows the pixel size and DPI, so the photo prints at the size you set.
Measured file size: BMP vs PDF
sharp 0.35.5 / libvips 8.18.7, 31 October 2026, long edge 1600 px; PDF saved as PixelFit's PDF writer, one page wrapping the quality 85 JPEG, BMP as computed: 24-bit uncompressed.
| Sample | BMP | Change | |
|---|---|---|---|
| portrait photo (1281×1600 px) | 5.87 MB (6,150,454 bytes) | 254 KB (260,507 bytes) | −96% |
| landscape photo (1600×1200 px) | 5.49 MB (5,760,054 bytes) | 641 KB (656,254 bytes) | −89% |
| scanned typed letter (1273×1600 px) | 5.83 MB (6,112,054 bytes) | 332 KB (339,628 bytes) | −94% |
| flat chart with a transparent background (1600×1000 px) | 4.58 MB (4,800,054 bytes) | 40.3 KB (41,225 bytes) | −99% |
What the numbers mean for BMP to PDF
Our portrait photo at 1281×1600 px: BMP 5.87 MB → PDF 254 KB (−96%, 23.6 times smaller).
Our landscape photo at 1600×1200 px: BMP 5.49 MB → PDF 641 KB (−89%, 8.8 times smaller).
Our scanned typed letter at 1273×1600 px: BMP 5.83 MB → PDF 332 KB (−94%, 18.0 times smaller).
Our flat chart with a transparent background at 1600×1000 px: BMP 4.58 MB → PDF 40.3 KB (−99%, 116.4 times smaller).
Per pixel, the portrait took 24.01 bits as BMP and 1.02 bits as PDF, a difference of 5.62 MB on 2,049,600 pixels.
Per pixel, the chart took 24.00 bits as BMP and 0.21 bits as PDF, a difference of 4.54 MB on 1,600,000 pixels.
PDF came out smaller than BMP on all 4 samples, from −89% to −99%.
The PDF is the JPEG plus a little structure: PixelFit's one-page PDF writer added only 729 bytes around the JPEG made from the BMP, so the PDF size is decided by the JPEG quality and pixel size inside it.
How to convert BMP to PDF
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Add the BMP file
Drop the .bmp, .dib file on the tool at the top of this page, tap to choose it, or paste it.
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Keep PDF selected
PDF is pre-selected. Add a maximum size in KB if a portal sets one; PixelFit lowers the JPEG quality inside the page until the PDF fits. Our BMP test portrait came out at 254 KB as PDF with no limit set.
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Download the PDF
Save the file ending in .pdf; its size in KB shows before you save.
BMP and PDF side by side
BMP (1990) next to PDF (1993); browser figures checked 31 October 2026.
| Property | BMP | |
|---|---|---|
| File extensions | .bmp, .dib | |
| MIME type | image/bmp | application/pdf |
| Compression | lossless | lossy or lossless |
| Transparency | no | yes in general; PixelFit pages are JPEG, so no |
| Animation | no | no |
| Largest size | 32,767 px per side | follows the embedded image |
| Colour depth | 1 to 32 bits per pixel | whatever the embedded image uses |
| Metadata | header resolution fields | document info and XMP |
| First published | 1990 | 1993 |
| Opens in | Chrome, Edge, Firefox, Safari (every current browser) | not read as an image input |
| Good for | old Windows programs and scanners that need raw pixels | document uploads, printing and sending several photos as one file |
| Weak for | anything you upload or e-mail, because pixels are usually stored uncompressed | profile pictures and web pages, which expect an image file |
| Specification | Bitmap Storage (Microsoft Win32 documentation) | PDF 2.0, ISO 32000-2 (Library of Congress format description) |
When not to change BMP to PDF
- Avoid PDF for screenshots, text, signatures and logos when the destination accepts PNG: JPEG compression softens hard edges; PNG keeps them sharp at a similar or smaller size: our flat chart was 39.7 KB as a full-colour PNG and 12.5 KB with 256 colours, against 40.3 KB as PDF.
- Do not upload a PDF where the form asks for a photo or signature image: those fields usually check for JPG or PNG, so a BMP photo for such a field should become a JPG instead.
- Keep the original BMP if a program or archive needs it; the PDF is for sending and uploading.
Browser support for BMP and PDF (October 2026)
Reading BMP (.bmp, .dib): Chrome, Edge, Firefox, Safari (every current browser).
Writing the PDF: PixelFit's own PDF writer (JPEG page images), every browser. The JPEG inside each page comes from canvas.toBlob, which Chrome 50+, Firefox 18+ and Safari 11+ support (MDN compatibility data, checked 31 October 2026).
Upload forms that ask for PDF
3 of the 61 application portals we checked accept PDF photos, 1 of them with a limit of 50 KB or less. A few of them, for this BMP file (verify with the official notice before you upload):
- Canada G5 sponsorship: PDF photo, up to 4 MB, 420 × 540 px (also takes JPG, PNG).
- Oman eVisa: PDF photo, up to 512 KB (also takes JPG, PNG).
- ICSI student: PDF photo, 20–50 KB (also takes JPG, PNG, GIF, BMP).
Where BMP files come from
BMP files usually come from old Windows programs, Paint, scanners or screenshots tools that store raw pixels. Because the pixels are uncompressed, a BMP photo is several megabytes, far above typical upload limits, and changing it to PDF fixes that.
Sources
- Bitmap Storage (Microsoft Win32 documentation), Microsoft Learn, checked 31 October 2026: learn.microsoft.com/en-us/windows/win32/gdi/bitmap-storage
- PDF 2.0, ISO 32000-2 (Library of Congress format description), Library of Congress, checked 31 October 2026: loc.gov/preservation/digital/formats/fdd/fdd000474.shtml
- MDN Web Docs, Image file type and format guide (which browsers decode BMP), checked 31 October 2026: developer.mozilla.org/en-US/docs/Web/Media/Guides/Formats…
- Test photo “President Barack Obama.jpg” by Pete Souza (Official White House photo), public domain, measured by PixelFit with sharp 0.35.5 / libvips 8.18.7 on 31 October 2026: commons.wikimedia.org/wiki/File:President_Barack_Obama.jpg
Frequently asked questions
Can I convert BMP to PDF for free?
Yes. The BMP to PDF change runs free on your device, with no sign-up and no upload, one file or up to 25 at a time; Pro raises the batch to 500 with one ZIP download.
How do I convert BMP to PDF?
Drop the BMP on the tool above, keep PDF selected, and download the .pdf file. Add a KB limit if the destination has one.
Does converting BMP to PDF reduce quality?
A PixelFit PDF page holds a JPEG, which is lossy: the exact pixels of the BMP are approximated, which is invisible on photos at high quality but can blur sharp text and edges. In our test a 1281×1600 px portrait went from 5.87 MB as BMP to 254 KB as PDF (−96%).
Why convert BMP to PDF?
PDF suits document uploads, printing and sending several photos as one file; BMP is a poor fit for anything you upload or e-mail, because pixels are usually stored uncompressed.
How big will the PDF from a BMP be?
About the size of the JPEG inside it: PixelFit's one-page PDF added 729 bytes around the portrait. Set a KB limit and PixelFit lowers the JPEG quality until the PDF fits.
Related
More BMP format changes
- BMP to JPG same BMP input
- BMP to PNG same BMP input
Other files to PDF
- GIF to PDF also ends as PDF
- JFIF to PDF also ends as PDF
- JPG to PDF also ends as PDF
- PNG to PDF also ends as PDF
- TIFF to PDF also ends as PDF