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
- Select your files, or drag them onto the box above.
- Click Process.
- Download the result. Nothing was uploaded at any point.
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.
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 |
Why uploads get rejected
Meeting the size is only part of it. These are the failures 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.
Who uses this
Scanned paperwork, receipts, signed forms, and any upload where size matters more than colour.
Other names for this tool
People look for this under several different names. If you arrived searching for any of the following, this is the right page — they all describe the same thing:
- image to pdf black and white
- jpg to pdf greyscale
- convert photo to black and white pdf
- grayscale pdf from images
- scan to black and white pdf
- image to pdf without color
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.
Are my files uploaded to a server?
No. Everything runs inside your browser on your own device. Your file is never transmitted and never stored by us. You can confirm it by opening your browser's Network tab while you use the tool — you will see no upload request.
Is this really free?
Yes — no account, no trial, no watermark and no cap on usage. It runs on your own device rather than our servers, so there is no cost for us to pass on.
Related tools
From other categories
Your files stay on your device. This tool runs entirely in your browser. No file is uploaded, transmitted, or stored. You can verify this by opening your browser's Network tab while using the tool.
Disclaimer. Specifications published by exam boards, governments and platforms change without notice. We verify and date every specification on this site, but you should always confirm against the official source before submitting an application. See our full disclaimer.