Image to PDF in Black and White
Convert your images into a single black-and-white PDF — far smaller than colour, and better suited to scanned paperwork.
Working…
Done
How to use this tool
- Choose your files, or drag them onto the box above. They are processed in the order you add them.
- Set a total size limit if the upload form has one, and tick black-and-white if colour is not needed — it usually halves the file.
- Click Process, then download. The page objects are copied rather than re-rendered, so text stays selectable and quality is untouched.
Greyscale is not only about printing cost. Colour information is most of the data in a photograph of a document, and discarding it typically cuts file size by half to two thirds with no loss of legibility — which is often exactly what an upload limit needs.
Image to PDF in Black and White — the specification
| Output | Greyscale PDF |
|---|---|
| Input | JPG or PNG, multiple files |
| Typical saving | Half to two thirds smaller than colour |
| Method | Luminance-weighted greyscale, not a channel average |
| Privacy | Runs in your browser |
Image to PDF in Black and White: what can go wrong
Most failures here are not about the document itself but about how it was produced. The ones that actually come up:
- The document relies on colour to be understood — a chart with colour-coded lines, or a form where red text means something.
- A file that is not actually an image despite its extension.
How it works
Each image is drawn to a canvas and converted to greyscale using the standard luminance weighting (roughly 30% red, 59% green, 11% blue) rather than a naive average — that weighting matches how the eye perceives brightness, so text and detail stay crisp instead of turning muddy.
The greyscale images are then encoded and assembled into a single PDF with pdf-lib. Pages appear in the order you added the images.
A measured run of this tool
Not an estimate. This page’s own code, run against a documented reference file.
Input: 1.88 MB. Output: 3.83 MB.
Who needs Image to PDF in Black and White
Scanned paperwork, receipts, signed forms, and any upload where size matters more than colour.
Image to PDF in Black and White — frequently asked questions
Why does black and white make the file smaller?
Because colour is most of the data. A photograph stores three channels per pixel; greyscale stores one, and it compresses better because there is less variation to encode. Halving the file size is typical and two thirds is common for scanned text.
Will my text still be readable?
Yes, usually more so. The conversion uses luminance weighting, which preserves the contrast between ink and paper that legibility actually depends on.
Does this reduce the quality of my PDF?
No. The page objects are copied across rather than re-rendered, so text stays text, images keep their original encoding, and the result is visually identical to what went in.
What happens to bookmarks, links and form fields?
Page content is preserved exactly. Document-level features such as bookmarks, internal links and form fields may not survive a structural edit, so check the output if your file relies on them.
Can I process a password-protected PDF?
Not while it is encrypted. Remove the password in whatever application you normally open it with, then process the unprotected file here.
Is this tool really free?
Yes. No account, no trial period, no watermark on the output and no cap on how many times you use it. The site is funded by advertising.
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Your PDF never leaves this device. Contracts, statements and applications are processed entirely in the browser — open the Network tab while you use the page and you will see no upload (how that works).
Disclaimer. Upload limits differ between portals and are often lower than the published figure once the whole application is counted. Check the limit shown on the upload screen itself. Full disclaimer.