Convert PDF to Grayscale
Remove all color from your PDF and convert it to black and white. Perfect for printing, archiving, and reducing file size.
How to Convert PDF to Grayscale
Upload Your PDF
Drag and drop your color PDF or click to browse. All processing happens locally in your browser — your file never reaches any server.
Automatic Conversion
Each page is rendered and converted to grayscale using a luminance-weighted formula (ITU-R BT.601) that produces natural-looking black and white output.
Download Grayscale PDF
Once complete, download your new grayscale PDF. Color PDFs typically shrink 30–60% in file size after conversion.
Frequently Asked Questions
Why convert a PDF to grayscale?
Grayscale PDFs are significantly smaller in file size, cheaper to print (no color ink), and required by some document submission systems that do not accept color files. They are also useful for accessibility compliance and archiving.
How much smaller will the grayscale PDF be?
It depends on the original content. PDFs with lots of color images typically shrink 30–60%. PDFs that are mostly text and already use little color may see minimal size reduction.
Does grayscale conversion preserve text as selectable/searchable?
No. This tool renders each page as a high-resolution image, so the resulting PDF is image-based. Text will no longer be selectable or searchable after conversion. If you need to preserve searchable text, a desktop PDF editor is recommended.
What DPI is used during grayscale conversion?
Pages are rendered at 144 DPI (2× PDF point scale) before grayscale conversion, which produces clean, sharp output suitable for printing and screen viewing.
Is the grayscale formula accurate?
Yes. PDFForge uses the ITU-R BT.601 luminance formula: Gray = 0.299×R + 0.587×G + 0.114×B. This weights each color channel according to how the human eye perceives brightness, producing more natural results than a simple average.
Can I convert a password-protected PDF to grayscale?
You need to remove the password first. Use our Unlock PDF tool, then come back to convert to grayscale.
Is my PDF file uploaded to a server?
No. Everything runs in your browser via WebAssembly (pdfjs-dist + pdf-lib). Your file is never sent to PDFForge or any third party.