Free · No sign-up · Runs in your browser

Convert a PDF to black and white.

Turn a colour PDF into greyscale for photos and slides, or pure black and white for crisp, photocopy-style text. Save ink, clean up phone scans, or meet an upload rule that asks for monochrome.

Not uploaded — nobody sees it Greyscale or pure B&W Cleans up grey scans No sign-up, no watermark

Drop your PDF here, or click to browse One PDF at a time · colour scans, slides, documents

Style

Quality

Your file is never uploaded — it’s processed right here in this browser tab, on your device. It never reaches a server, so we never see it, copy it or keep it.

At a glance

PDF to black and white: quick facts

Turn a colour PDF into greyscale or pure black and white.

Updated 8 October 2026

Price: Free. No sign-up, no watermark.
Modes: Greyscale (keeps photos and charts readable) or black and white (two tones, for text and scans).
Quality: Standard 150 dpi or High 220 dpi.
Note: Pages are redrawn as images, so text is no longer selectable.
Privacy: Your file is processed in your browser and never uploaded.

How it works

How to make a PDF black and white

Each page is drawn at the quality you pick, every pixel’s colour is turned into its brightness (using the standard weighting the eye uses), and the page is rebuilt into a new PDF at exactly the same size.

Add your PDF

Drop in a colour PDF: a scan, slides, a form or a report.

Pick a style

Greyscale keeps shades; black and white uses only black and white. Choose a quality.

Download

Your file ends in -greyscale.pdf or -black-and-white.pdf.

Tips

Getting a clean black-and-white result

Different documents need different settings. These are the quick rules.

Text documents and forms: black and whiteIt gives the sharpest text and the smallest file, and is closest to a photocopy.
Phone scans with a grey backgroundUse black and white with “Clean background”. Grey paper and shadows turn white and the text stays solid.
Faint pencil, stamps or light highlightsUse “Keep faint marks”, or switch to Greyscale, so pale marks don’t disappear.
File too big afterwards?Greyscale pages are stored as images. Run the result through Compress PDF and set a target size.

Like every Altto tool, this runs on your device — nothing you add is uploaded. How Altto works

3 → 1

colour channels become one brightness value per pixel. Red, green and blue are weighted 30%, 59% and 11%, the way the eye sees brightness, so coloured text doesn’t vanish.

Which style?

Greyscale or black and white?

Pick by what’s on the page.

Choosing a style for your document
Document	Best style	Why
Letters, contracts, typed forms	Black & white, Normal	Sharpest text, smallest file
Phone or tablet scans	Black & white, Clean background	Removes shadows and grey paper
Slides, charts, reports with photos	Greyscale	Keeps shading so charts stay readable
Handwriting in pencil, faint stamps	Greyscale, or B&W with Keep faint marks	Keeps pale marks visible

FAQ

Frequently asked questions

How the conversion works and which setting to use. To shrink the file too, see Compress PDF.

What’s the difference between greyscale and black and white?

Greyscale turns every colour into a shade of grey, so photos, charts and coloured highlights stay readable. Black and white uses only two tones, pure black and pure white, which is ideal for text documents, forms and scans: the text gets crisper, grey scan backgrounds disappear and the file is usually smaller.

Will my text still be selectable?

No. To convert every element reliably, including images, vector drawings and coloured text, each page is redrawn as a high-resolution image. It prints sharply but the words are no longer selectable or searchable. If you need that back, PDF to Word can read the pages with OCR.

Why convert a PDF to black and white?

To save colour ink and toner, to meet a court, council or job portal rule that asks for monochrome documents, to make a phone scan look like a clean photocopy, or to see how a document will look on a black-and-white printer before you send it.

Which quality should I choose?

Standard (150 dpi) is fine for reading on screen and everyday printing, and keeps the file a sensible size. High (220 dpi) gives finer detail for small print, signatures and documents you’ll print large or archive.

Can I just print in black and white instead?

Yes, if you only need a paper copy, your printer’s greyscale option does the job. Converting the PDF helps when you need to send or upload a black-and-white file, or when a printer’s own conversion makes coloured text too faint.

Is my PDF uploaded?

No. Each page is drawn and converted inside this browser tab on your own device, and the new PDF is built there too. Nothing is sent to a server.

More tools