Convert a PDF to grayscale
Convert a colour PDF to black and white shades for printing or smaller scans. Output is image-based.
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Every page is rendered as a grayscale image at the resolution you choose and rebuilt into a new PDF.
The text becomes part of an image: it can no longer be selected, searched or copied, and links and form fields are removed. Keep your original.
Processed on this device with your browser. Nothing is uploaded.
How it works
Printing a colour PDF on a black-and-white printer, or submitting a scan to a portal that wants grayscale, is easier with a grayscale file. Each page is rendered with pdf.js at the resolution you choose, converted to shades of grey and rebuilt into a new PDF.
Be aware of the trade-off: the pages become images, so their text can no longer be selected, searched or copied, and links and form fields are removed. It suits scans and print jobs; keep the original for anything you need to edit or search, or run OCR PDF on the result.
What to expect from a grayscale conversion
| Your PDF | File size afterwards | Suggested resolution |
|---|---|---|
| Colour scan of documents or IDs | Usually smaller | 150 dpi; 200 dpi for small print |
| Photos, brochures, colour charts | Similar or smaller | 150 dpi |
| Text PDF exported from Word or a browser | Often larger, because text becomes an image | Better not to convert; print it in grayscale instead |
| Pages you will OCR afterwards | Depends on the source | 300 dpi, which OCR reads best |
If you only need a black-and-white printout, choosing grayscale in your printer settings keeps the text selectable and costs nothing; convert the file itself when a portal asks for a grayscale document or the colour scan is too big.
How to use it
- Choose a PDF.
- Pick the resolution (150 dpi is a good default).
- Click Convert to grayscale.
- Download the grayscale PDF.
Frequently asked questions
Are my files uploaded?
No. The file is read and processed by your browser on your device; nothing is sent to a server. The PDF engine is downloaded from this site the first time you use a tool and then runs on your device.
Why is the text no longer selectable?
Browsers cannot rewrite the colours inside arbitrary PDF content, so each page is converted to a grayscale picture. Run OCR PDF afterwards to make it searchable again.
Will the file be smaller?
For colour scans, usually yes. For text-only PDFs made by a word processor it can be larger, because text becomes an image.
Which resolution should I choose?
150 dpi for most documents, 200-300 dpi for small print or when you will print the result, 100 dpi for the smallest file.
What if my PDF is password-protected?
The tool will say so. If it is your file and you know the password, remove the protection with Unlock PDF first, then use the unlocked copy here.
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