Convert your PDF to grayscale by rasterizing and re-rendering each page. The output is image-based, so text is no longer selectable.
Select a PDF file to convert to grayscale. Processing time depends on the number of pages.
This tool rasterizes each PDF page to an image, applies grayscale conversion, and embeds the resulting images into a new PDF. The output PDF is typically larger than the original, but all pages are rendered at high quality (1.5× scale). Text in the output is no longer selectable—if you need selectable text, consider using dedicated PDF editing software.
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What is the Grayscale PDF?
Grayscale conversion transforms a full-colour PDF into a black-and-white document using luminosity-weighted pixel averaging. Unlike simple desaturation filters, this method produces natural-looking gray tones that preserve contrast and readability. The output is rasterized (image-based) rather than vector-based, meaning text is no longer selectable but rendering quality remains high.
How it works
The converter uses pdf.js to load your PDF and render each page to a canvas at 1.5× scale for clarity. A luminosity-based grayscale filter (29.9% red + 58.7% green + 11.4% blue) is applied to each pixel to match human perception of brightness. Each rasterized page is then embedded as a JPEG image into a new PDF document created with pdf-lib, and the final file is ready to download.
How to use the Grayscale PDF
Click 'Upload PDF' and select your PDF file from your computer
The tool will render each page to a grayscale image at high resolution (1.5× scale)
A new PDF is automatically created with all pages as grayscale images
Your download will start automatically—no account or cloud upload required
The output file is named [original-name]-grayscale.pdf
Benefits
Free and instant—no watermarks, no file size limits, no registration needed
Privacy-first—your PDF is processed entirely in your browser; nothing is uploaded to servers
High quality—pages are rendered at 1.5× scale and exported as JPEG to preserve clarity
No loss of content—all pages, images, and layout are preserved; only colour is removed
Perfect for printing—grayscale PDFs use less ink and are faster to print than colour originals
Accessibility friendly—grayscale can improve contrast for certain types of colour blindness
Frequently asked questions
Is the output grayscale true color or just desaturated?
The output uses luminosity-weighted grayscale (0.299×R + 0.587×G + 0.114×B), which matches human perception of brightness. This is mathematically more accurate than simple desaturation and produces natural-looking gray tones.
Will text in the output PDF still be selectable?
No. Because the output is rasterized (rendered as images), text is no longer selectable or searchable. If you need selectable text, use dedicated PDF editing software instead. The grayscale rendering remains sharp and readable for screen viewing or printing.
Why is the output file larger than the original?
Rasterization converts vector content (text, shapes) into pixel data. JPEG compression (quality 0.85) keeps file size reasonable, but image-based PDFs are typically larger than vector PDFs. This is a trade-off for visual consistency across all pages.
How long does it take to process a large PDF?
Processing time depends on page count and page complexity. A 100-page document typically takes 30–60 seconds. All processing happens in your browser, so speed depends on your device and available RAM.
Can I process PDFs with scanned images or mixed content?
Yes. The tool treats every page the same way—it renders the page as-is and converts it to grayscale. Scanned PDFs, complex layouts, and mixed vector/image content all work.
Is my PDF data stored or tracked?
No. Your file is processed entirely in your browser's memory and never uploaded. Once you close the page or refresh, no trace of your PDF remains.
What if the conversion looks strange or has artifacts?
Artifacts are rare but can occur with very high-resolution originals or complex layouts. Try re-uploading. If the issue persists, your original PDF may have unusual encoding; try exporting a fresh copy in your PDF editor and retrying.