Make a PDF Black and White
You scanned a form in color, and now it has to print on the office laser printer or go to an upload form that wants a black and white document. This page is tuned for exactly that: colored ink stays dark, the off-white paper of a phone scan turns clean white.
PDF to Grayscale
or drop PDF files here ·
Max 95 MB per file· Up to 20 files· Deleted after 30 minutes
Files are processed on our servers and deleted after 30 minutes.
Images only keeps colored text and links (useful for saving printer ink on photos); text and graphics only leaves photos in color.
Page numbers or ranges separated by commas, e.g. 1-4, 9.
0 keeps the original tones. Positive values darken text and lighten backgrounds of faded scans.
Images above this DPI are downsampled. 150 is fine for reading and office printing.
How to use this tool
- 1
Upload the color PDF
Drop in the scan or exported file. Up to 20 PDFs at once, each up to 95 MB.
- 2
Keep the scan-friendly settings
This page sets Convert to Black & white, Threshold 150 and Contrast +10 so blue and red ink stay black. Change them under Advanced settings only if the preview needs it.
- 3
Convert and check one page
Press Convert, zoom in on a signature or stamp, then download the black and white PDF.
Printing in grayscale changes only the printout; converting the PDF changes the file itself, which is what an upload form or a colleague's printer will see.
Make a PDF black and white for a monochrome printer
A monochrome laser printer cannot ignore color; its driver translates every color into a pattern of black dots. Pale backgrounds from a phone scan become a gray haze, colored table shading turns into a dotted fill, and light colored print can vanish. Converting the PDF first lets you see the result on screen and fix it before paper is wasted.
Pure black and white is the right result for text-heavy scans: forms, letters, invoices and handwritten notes. It removes the paper tint entirely and prints quickly. If the document holds photos or shaded charts, use grayscale PDF instead, which keeps their tones. The scale below shows approximate lightness from 0 to 255 using the common ITU-R BT.601 weighting, where green counts most and blue least; real scans add paper tint, so treat the values as a guide.
Which colors turn black, and which disappear
- Blue 29
Pure blue is very dark; always black
- Red 76
Red ink and stamps stay black
- Cutoff 150
This page's threshold
- Orange 173
Orange print turns white
- Sky 205
Light blue shading vanishes
- Yellow 226
Highlighter is lost
When a form asks for a black and white PDF
Paper forms have long asked for black ink because copiers and scanners pick it up reliably; USCIS form instructions, for example, ask applicants to type or print in black ink. Upload portals carry the same idea into files: a two-tone document is small, reads cleanly and photocopies well when someone prints it at the other end. If you filled a form in blue pen and scanned it in color, this conversion turns the ink black without rescanning.
Make PDF black and white in a print dialog instead
Chrome or Edge
- 01Open the PDF in the browser
- 02Press Ctrl+P or Cmd+P and choose your printer
- 03Set Color to Black and white, where the printer offers it
- 04Print; the PDF file itself stays in color
Adobe Acrobat Reader
- 01Open the PDF and choose File > Print
- 02Tick Print in grayscale (black and white)
- 03Print; nothing is saved to the file
Preview on a Mac
- 01Choose File > Print and click Show Details
- 02Look for a black and white or color mode option in the printer's section
- 03Names differ by printer driver
- Signatures and stamps are still solid black
- Small print in boxes and footers is readable
- No gray speckles where the paper was shaded
- Page order and page count match the original
- File size fits the form's limit, if it has one
Make PDF black and white: questions
Why is the threshold on this page 150 instead of 128?
Color scans of forms often carry blue or red ink and colored printed boxes, which sit in the darker middle of the scale. A slightly higher threshold keeps them black, while white paper is still far above it and stays white.
My yellow highlighter disappeared. Can I keep it?
Not in pure black and white: yellow is almost as light as paper, so it falls on the white side of any sensible threshold. Switch Convert to Grayscale and the highlight survives as a light gray band behind the text.
The form says 'black and white scan'. Is grayscale acceptable?
Often it is, since many people use the phrase loosely, but you cannot be sure. When the form gives a file size limit as well, a true two-tone file is the safer choice, because it is usually much smaller.
Why does my phone scan turn into gray speckles?
Shadows and uneven lighting push parts of the paper below the threshold. Lower Threshold toward 120, or rescan the page in even daylight without your hand's shadow across it.
Can I make a PDF black and white on my phone?
Yes, this page works in mobile Safari and Chrome. Pick the PDF from Files or Downloads, press Convert, and save the result back to the same place.
After converting, the PDF is still too big for the form. What next?
Run it through compress PDF to 200 KB or the size your form names. Two-tone pages compress far better than color ones, so the second step usually gets there easily.