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PDF to Grayscale Converter

Convert every page of a PDF into a grayscale image. Upload a PDF, choose a resolution, and download each page as a black-and-white PNG file.

Category: documents
Use Case: Printing Preparation, Document Scanning Look, File Size Reduction
Privacy: 100% browser-based

Click to upload a PDF file

Your file is processed entirely in your browser

Recommended Settings

Pro Tips

  • Grayscale conversion uses the standard luminance formula (0.299R + 0.587G + 0.114B) to match how the human eye perceives brightness
  • Colors are removed but overall contrast and detail are preserved, unlike a simple black-and-white threshold
  • Higher resolution multipliers produce sharper images but larger file sizes - 2x is a good default for most uses
  • The whole file is rendered locally in your browser using PDF.js - nothing is uploaded anywhere

Most Popular

Most users convert at 2x resolution for a good balance of quality and file size

When to Use This Tool

Printing Preparation

Convert PDF pages to grayscale before printing on a black-and-white printer, so colors don't get misinterpreted or wasted as ink.

Document Scanning Look

Give a color PDF the appearance of a black-and-white scanned document for a consistent archival look.

File Size Reduction

Grayscale images often compress smaller than color images, useful when file size matters more than color fidelity.

Accessibility Testing

Preview how a colorful document appears to users with color vision deficiencies by converting it to grayscale.

How It Works

1

Read the uploaded PDF file as binary data directly in your browser

2

Parse the file into a PDF document using the PDF.js library

3

For each page, render its full content onto an HTML canvas at the selected resolution

4

Read the canvas's pixel data and convert each pixel's RGB values to a single luminance-weighted gray value

5

Write the grayscale pixels back to the canvas and export it as a PNG image

100% Private

Files never leave your device. All processing happens locally in your browser.

Lightning Fast

Powered by PDF.js for optimal performance on modern browsers.

Open Source

Built with verified, open-source libraries. Fully transparent.

Frequently Asked Questions

How is the grayscale value calculated?

Each pixel's gray value is calculated as 0.299×Red + 0.587×Green + 0.114×Blue, a standard weighting that matches human perception of brightness better than a simple average.

Is this different from just removing color saturation?

The result is similar to desaturating an image, but this luminance-based formula produces more perceptually accurate brightness levels than a naive RGB average.

Why is the output a PNG instead of a color format?

PNG is used because it's lossless, preserving the exact grayscale values without introducing compression artifacts that could reduce document clarity.

Is my PDF uploaded to a server?

No. The entire file is read and processed locally in your browser using the PDF.js library. Your document never leaves your device.

Can I convert just one page to grayscale?

This tool converts every page in the document. If you only need one page, you can delete the others first using the Delete Pages from PDF tool.