Color printing costs a fortune in ink and toner — and most documents don't need color at all. Here's how to convert a PDF to black and white (grayscale) for free, on any device, without uploading your file anywhere.
Short answer: open the PDF, choose Print, set the destination to “Save as PDF” (or “Microsoft Print to PDF”), enable the Black and white / Grayscale option in the print settings, and save. On a Mac, Preview's File → Export as PDF → Quartz Filter → “Gray Tone” does the same. The result is a proper grayscale PDF — much cheaper to print.
Three reasons, all about money and practicality. Cost: color toner/ink costs roughly 3–5× more per page than black — a 200-page color report can cost €10–15 to print versus €2–3 in grayscale. Speed: most printers rip through black-and-white pages noticeably faster. Size: grayscale PDFs are usually smaller than their color originals, which also makes them friendlier to email.
The best candidates are text documents, invoices, contracts, lecture notes, forms and anything where color carries no information. The worst candidates are charts, maps and annotated documents where color means something — more on that below.
A black toner cartridge prints ~2,000–3,000 pages; a color set costs multiples more for the same yield. For offices and students printing hundreds of pages, grayscale-by-default is one of the easiest cost cuts there is.
Dropping two color channels typically shrinks the PDF noticeably — handy when the file also needs to be emailed. Pair it with our compressor for maximum shrinkage.
A red-vs-green bar chart becomes two similar grays. Before converting reports, switch charts to patterns or labels — or keep one color copy for screen and a grayscale copy for print.
Most printers let you set “black and white” as the default in their driver preferences. Do it once and you'll stop accidentally printing color forever.
On iPhone/Android, open the PDF, Share → Print → pinch-to-zoom the preview → Share as PDF gives you a new PDF; pair with a grayscale print option where your print service offers it.
Color originals matter for legal, medical and design documents. Convert a copy for printing; never overwrite your only color version.
Highlights, red-ink corrections, color-coded categories — all become shades of gray. If color carries meaning in your document, grayscale will silently destroy that meaning.
Grayscale photos lose depth and can look muddy, especially low-contrast images. Fine for reference prints; not for anything presentational.
You cannot convert a grayscale PDF back to color. The color data is gone. Always convert a copy and keep the original.
A few print drivers claim grayscale but still embed color data (and still drink color ink). Verify the output file is truly gray — zoom into an image and check, or print a test page.
Usually yes — dropping the color channels removes roughly two-thirds of the image data, so grayscale PDFs are often noticeably smaller. For maximum reduction, follow up with a compression pass.
No. Grayscale conversion permanently discards the color information. That's why you should always convert a copy and keep the original color PDF archived.
Because colors that were distinct (red vs green vs blue) map to similar shades of gray. Fix it before converting: use patterns, textures or direct labels on chart elements instead of relying on color alone.
Yes, substantially. Black toner/ink costs far less per page than color, and most documents print identically well in grayscale. Offices that switch to B&W-by-default typically cut print costs by half or more.
For text: none — black text on white is already grayscale. For photos and graphics: some depth and distinction is lost, which matters for presentations but rarely for everyday documents.
It depends on the tool — many upload your file to their servers. The methods on this page use your own device's print system, so your document never leaves your computer at all. That's the safest option for sensitive files.
Yes. First extract the pages you want in black and white with a split tool, convert just that part via the print-to-PDF method, then merge the grayscale section back with the color pages. It takes two minutes and gives you a hybrid document — color where it matters, cheap grayscale everywhere else.