How to convert a PDF to grayscale

You have a PDF full of colour, and you want it grey. Perhaps you are about to print a stack of copies, or a form has a coloured banner you would rather not spend ink on. A grey copy takes a few clicks to make.

Before you start, one thing deserves a plain warning. Grayscale PDF draws every page in grey and saves it as a picture. That means the text in the new file is part of the picture. This guide shows the steps and what you give up, so you can decide if it fits.

How do I convert a PDF to grayscale?

Add the PDF to Grayscale PDF, choose a picture quality of 150, 200 or 300 DPI and press Make PDF grayscale. Download the new file from the result screen. Your original is never changed, so you end up with two files: the colour one and the grey one.

1. Open Grayscale PDF and drop your PDF onto it, or choose the file from your device. Colour pages, scans and photos all work.
2. Pick the picture quality. 150 DPI suits reading on screen, 200 suits most printing and 300 is for fine print.
3. Read the note under the choices. It says the text becomes part of the picture.
4. Press Make PDF grayscale.
5. Download the new PDF. The result shows its size next to the size of the file you added.
6. Open the grey copy and look at each page before you print or send it.

Does converting to grayscale turn my text into a picture?

Yes. To turn colours to grey, each page is drawn and saved into a new PDF as a picture. You can no longer select, copy or search the text, and links and form fields are gone. A digital signature does not survive. You can get searchable text back with OCR PDF.

This is the big trade-off, so here it is in one list.

• Lost: selectable and searchable text, links, form fields and digital signatures.
• Kept: how the pages look, now in shades of grey.
• Never touched: your original file.

If you need the words to stay as text, keep using the original for anything that has to be searched or filled in. Use the grey copy for printing. To read the words back in, run OCR PDF on the grey copy. It reads the pages in your browser and adds the words as hidden text. Accuracy depends on the pages, and sharp, straight, printed pages read best.

Which quality should I pick: 150, 200 or 300 DPI?

Pick 150 DPI to read on screen, 200 DPI for most printing and 300 DPI for fine print. Higher is sharper and makes a bigger file. DPI means dots per inch, so more dots give a finer picture. If you are unsure, start with 200 and look at the result.

Will the grey file be smaller or bigger?

It depends, and the result screen shows the size before and after. A page of plain text can get larger, because a picture holds more than the words did. A page full of colour photos often gets smaller. If the file is too big, choose 150 DPI.

For more help with big files, read why your PDF is so big or use Compress PDF.

Is grayscale the same as black and white?

Almost, but not quite. Grayscale keeps shades of grey, so photos and shading still look right. True black and white has only black and white dots. This tool makes grayscale. On most printers, grey pages print with black ink, which is what most people want. Check your printer's preview to be sure.

A worked example

Say a freelancer has a signed contract with a coloured logo and a coloured table, and needs three printed copies. They add the PDF to Grayscale PDF and pick 200 DPI. The result screen shows the new size next to the old one. They download the grey file, check each page and print from it.

They keep the original colour PDF too. When the client asks for the contract by email, the freelancer sends the original, because it has the real text, and the grey copy would be a picture of it.

What about a scanned PDF?

It works. A scan is already a picture, so each page is drawn in grey and the words look as they did. If the scan had searchable text from OCR, that hidden text is lost, so run OCR PDF again on the grey copy.

If you are starting from paper, Scan to PDF lets you choose Original, Grey or Black and white for each page while you scan.

Common problems and fixes

• You cannot select the text in the grey copy. This is expected, because the pages are pictures. Use the original, or run OCR PDF on the grey copy.
• The grey file is bigger than the colour one. Plain text pages can grow when drawn as pictures. Try 150 DPI, or use Compress PDF.
• The print looks soft. Make the grey copy again at 300 DPI.
• Links or form fields stopped working. They are gone in the grey copy. Fill the form in first, or use the original.
• A signature no longer verifies. A digital signature does not survive, so keep the signed original for anything that needs it.
• You wanted to keep the text as text. This tool cannot do that. It draws the pages as pictures.

Where does your file go?

Nowhere. Your pages are drawn in grey in your browser, so the PDF is not sent to our servers. Your original file is not changed either. That helps when the pages hold contracts, statements or anything else you would rather keep private.

A short checklist

• Keep the colour original.
• Pick 150, 200 or 300 DPI, then compare the sizes on the result screen.
• Open the grey copy and look at every page.
• Use the grey copy for printing, and the original for anything that needs real text, links or a signature.

2 free uses in total, no account needed. Free files can be up to 50 MB, and Pro allows up to 500 MB.

Sources

• PDFinish's own Grayscale PDF page, for the quality choices, the pages being saved as pictures, what is lost and the browser-only processing, as of November 2026.