How to Convert a PDF to Black and White (Free Guide)

By PDFKits Team — Published July 2, 2026

How to Convert a PDF to Black and White

Color PDFs look great on screen but cost more to print and produce larger files. Whether you want to save on ink, shrink a document, or meet a submission requirement, knowing how to convert pdf to black and white gives a clean, professional result in seconds. You can optimize and recolor a PDF online, and this guide explains grayscale vs true monochrome so you pick the right one.

Grayscale vs True Black and White

TypeKeeps gray shades?Best forFile size
GrayscaleYesPhotos, gradientsSmaller than color
True black & whiteNo (pure B/W)Text, line art, faxesSmallest

Method 1: Convert a Color PDF to Black and White Online

  1. Open the PDFKits optimize PDF tool in your browser.
  2. Upload your color PDF.
  3. Choose grayscale (or black and white).
  4. Download the converted PDF.

The file is processed in your browser and never uploaded, keeping confidential content private.

Method 2: Print to PDF in Grayscale

Open the PDF, press Ctrl+P (or Cmd+P), choose Microsoft Print to PDF or Save as PDF, and enable Grayscale in the print settings. Honest limitation: some print drivers keep hidden color data, so the file may not shrink much, use a dedicated tool if size matters.

Method 3: Convert PDF to Black and White, Not Grayscale

If you need true monochrome rather than gray shades, use a tool that offers a black-and-white or bitonal mode. This is common for archived documents and faxes where pure black text keeps file sizes tiny and edges sharp.

Why Convert to Black and White?

Black and white PDFs print cheaper, scan faster, and produce smaller files. To shrink them even more for email, compress the PDF after converting.

Frequently Asked Questions

How do I convert a pdf to black and white for free? The free PDFKits optimize tool converts color PDFs to grayscale or black and white at no cost.

What is the difference between grayscale and black and white? Grayscale keeps gray shades; true black and white uses only pure black and white pixels.

Will converting reduce my file size? Usually yes, especially with true monochrome, which removes color data.

Conclusion

Converting a PDF to black and white saves ink, shrinks files, and gives a clean, formal look. For a quick, private conversion with grayscale and true monochrome options, use the PDFKits optimize tool in your browser.

→ Try optimize PDF — Free & Online