Grayscale PDF — Convert a Color PDF to B&W
Browser tool that turns every page of a color PDF into a grayscale picture and saves a black-and-white PDF
Runs in your browser · nothing is uploaded
Drop the PDF to turn grayscale here
One PDF (up to 100 MB). The file never leaves your browser.
What it does
This tool turns a color PDF into a black-and-white one. Use it when a form must be submitted in black and white, to see how a document will look from a monochrome printer, or to make a print copy that saves color ink. Every page is drawn as it appears on screen and each pixel is replaced by the gray of matching brightness, so photos, charts and highlighter marks all become gray.
How to use
- Drop one color PDF on the box or press Choose PDF.
- Choose the resolution (150 dpi by default).
- Press Make grayscale PDF. Progress is shown page by page; press Stop if it takes too long.
- Check the size change and download
name-grayscale.pdf.
How it works
- Formula: the gray level uses the ITU-R BT.601 luma weights: gray = 0.299 × red + 0.587 × green + 0.114 × blue, computed in integers and rounded. Red text becomes dark gray; yellow highlighter becomes very light gray.
- Method: PDF.js renders each page, the gray picture is stored as a JPEG (quality 85%) and the page keeps its original size.
- Lost in the result: selectable and searchable text, links, form fields, bookmarks and comments. Your original file is not changed.
- Device limits: on devices with small canvas limits (phones) large pages may be drawn below the chosen resolution; the result says so when that happens.
- Limits: files up to 100 MB. PDFs that ask for a password, or have editing restrictions, are not processed.
Examples
| Resolution | A4 page in pixels | Good for |
|---|---|---|
| 100 dpi | 827 × 1169 | Checking on screen, light sharing |
| 150 dpi | 1240 × 1754 | Everyday printing, submissions |
| 200 dpi | 1654 × 2339 | Documents with small print |
| 300 dpi | 2480 × 3508 | High-quality printing |
To shrink a PDF while keeping its text, use Compress PDF; to turn pages into pictures in full color, use Rasterize PDF.
FAQ
Can it keep the text and change only the colours?
No. The tool draws each page and turns the picture gray, so the result's text cannot be selected, searched or copied, and links and form fields are lost. Rewriting every colour inside a PDF depends too much on how each file is built to give reliable results.
Is my PDF uploaded?
No. Rendering, the gray conversion and saving all happen in your browser; the file is never uploaded.
Which resolution should I pick?
150 dpi is enough for screens and everyday printing. Choose 200–300 dpi for small print or fine lines. Higher resolutions make larger files and take longer.
Will the file get bigger or smaller?
It depends. Color PDFs full of photos usually shrink; light text-only PDFs can grow because their pages become pictures. The change against the original is shown next to the result.
Related tools
Rasterize PDF
Browser tool that renders every PDF page as an image at the chosen resolution and saves an image-only PDF
Compress PDF
Browser tool that recompresses the images inside a PDF as JPEG to cut the file size while keeping text intact
Scan to PDF
Browser document scanner with 4-point perspective correction, B&W cleanup and multi-page PDF output
PDF to JPG
Render PDF pages to JPG or PNG at a chosen DPI and download a ZIP, in the browser