Language: English

Make a PDF grayscale

To make a PDF grayscale without uploading it, open Grayscale PDF on GustKit, drop the PDF, and leave 150 dpi. Press Make grayscale. pdf.js paints each page, the canvas replaces color with brightness, and pdf-lib saves a new PDF. The original stays put. Words in the result are pixels, so you cannot select or search them. 72 dpi is a lighter file. 200 dpi paints more pixels into the same page size.

  1. Choose file
  2. Set options
  3. Get result

Limits in your browser: 500 MB · 3,000 pages.

Your file never leaves your device. Processed locally in your browser. Nothing is uploaded.

Each page is painted and saved as gray. Text in the new PDF is not selectable.

Drop a PDF and download a black-and-white copy. pdf.js paints every page, the canvas replaces color with brightness, and pdf-lib saves a new file. Nothing is uploaded.

Paint a PDF gray and save a new file

Grayscale PDF uses pdf.js to paint every page, then replaces color with brightness. pdf-lib embeds those pictures in a new PDF. The original stays put. Words in the result are pixels.

A photocopy in gray

150 dpi is the start. 72 is lighter and 200 paints more pixels into the same page size. A password has to be removed first.

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Text you cannot highlight

Compress PDF can shrink photos and still leave selectable words. This page trades that away. Copy a sentence from the original, not from the gray file. To join several PDFs, use Merge PDF.

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How to make a grayscale PDF

  1. A photo is refused. Unlock a password on the unlock page first.

  2. Leave 150 dpi unless you want a lighter file at 72 or a print at 200.

  3. Press “Make grayscale” and keep the tab in front while the pages paint.

  4. Compare one page with the original. The signature on the old file does not come along.

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Gray pages without sending the document

  • New file

    The download is a different PDF. The one you dropped is unchanged.

  • Whole page

    Headings, lines and photos all become gray pixels.

  • Same page size

    Inches stay. Dpi only changes how many pixels fill the rectangle.

  • Painted here

    pdf.js and pdf-lib run in this tab.

  • No old title

    The new file does not copy the previous author or title.

  • Free for everyone

    The notice shows 500 MB and 3000 pages. Browser memory can stop sooner. This page has no paid plan.

Questions about grayscale PDFs

Will the gray PDF be smaller?

Often, because each page is a JPEG at quality 0.85. A tight scan can still grow.

Can I search the gray copy?

No. Search and copy need the original, or OCR PDF later.

Does 200 dpi enlarge the page?

No. The point size stays. More pixels are painted into it.

What about a signature?

It does not carry. The gray file is a new document.

Is this the same as grayscale image?

No. That page grays a photo. This one grays PDF pages.

Are my pages uploaded?

No. Painting and saving stay in this tab.

Which dpi to pick

DpiWhat you get
150 dpi, defaultThe control starts here. It fits a form or a slide.
72 dpi, lighter fileFewer pixels in the same page size. The file tends to be lighter. Fine for a look on screen.
200 dpi, more pixels for printMore pixels in the same point size. Inches do not change. Use it when the gray page will be printed.