Convert a PDF to black and white
Print-ready black and white in one click, with the text still searchable.
- Nothing is uploaded
- Works offline after first visit
- Open source
- No watermark · limit is your device’s memory; phones hold less
Make a colour PDF black and white for printing, a court filing or a portal that asks for it. It is free, needs no account and adds no watermark, and your files are not uploaded: everything runs in your browser on your device. The size limit is your device’s memory, and phones hold less; give the page a short while after one visit to save itself for offline use, and then it works offline.
Done
Open the network tab. Your files never appear in it.
Add files and run the tool to see every request this tab makes.
Your files are processed on this device and never sent to a server. Reload the page to clear everything from memory.
Plenty of places still want documents without colour: e-filing systems for courts, visa and grant portals, university submission rules, and print shops quoting a cheaper mono rate. A printer set to black and white will do it on paper, but when the file itself has to be black and white, you need a converted copy.
Drop the PDF and you get that copy in a moment. Each colour becomes the grey of the same brightness, the way a black and white photocopy would show it, while the text stays real text: you can still search it, copy from it and zoom in without blur. The file stays almost exactly the same size.
Strictly speaking the result is grayscale, with shades of grey for photos and coloured areas, which is what black and white means in nearly every submission guideline. It is made in your browser, so the document is not sent anywhere.
How it works
- Drop one or more colour PDFs.
- Press Make black and white.
- Download the copies and send or print them.
In your browser, not on a server
pdf-lib (MIT) opens the PDF in your tab and draws one neutral grey rectangle over each page with the PDF Saturation blend mode. Blending keeps the brightness of whatever is underneath and takes the grey’s zero saturation, so every colour, in text, drawings and photos alike, turns into its own shade of grey. Nothing on the page is rewritten or re-rendered, so text stays text. For the same reason the original colour data is still in the file: the page looks and prints grey, but a check that inspects colour spaces may still detect colour.
Compared with upload-based tools: Most online converters rasterise every page to make it grayscale, which uploads your document, makes text unselectable and often makes the file much larger. Here nothing leaves your device, text stays sharp and searchable, and the file grows by a few hundred bytes.
Verify it yourself. Give the page a short while after one visit to save itself for offline use, then turn off Wi-Fi or switch to airplane mode and run the tool again. Or open your browser's developer tools (F12, or Cmd-Option-I on a Mac), pick the Network tab, and watch it while you convert. The panel above does the same count for you.
Questions
Is it pure black and white or grayscale?
Grayscale: photos and coloured shapes become shades of grey so they stay readable. Black text stays black. That is what printers and filing systems mean by black and white; pure two-tone output would turn photos into blotches.
Will a court or portal accept it?
The pages look and print grey, which is what most of those rules are after. But the original colour data stays inside the file, so a system that inspects colour spaces may still flag it as colour. If a portal or print shop rejects it, print the PDF to a new PDF in greyscale from your PDF reader, or run it through a preflight tool. Hyperlinks and bookmarks keep working and the text is searchable, which many e-filing systems also require.
Can I check the result before printing?
Yes. Open the downloaded copy in any PDF reader. It shows exactly what a mono printer will print, which is a quick way to see whether a chart still reads without colour.
Is the file uploaded anywhere?
No. There is no server in this process. The page is a static file and the work is done by code running inside your browser tab. Give the page a short while after one visit to save itself for offline use; then you can turn off Wi-Fi and it still works.
More PDF tools
Grayscale PDF
Every colour becomes its own shade of grey, and the text stays text.
Crop PDF
Cut PDF pages down to what matters: draw the area to keep, or trim the white margins automatically.
Redact PDF
Find a name or number and black it out for good, or draw boxes by hand. The document stays on this device.
File Checksum
Get a file's checksum on your device and compare it with the one the publisher lists.
Other conversions
Guides
- How to make a PDF black and whiteChoosing black and white when you print only changes the paper. If a portal or a printer wants the file itself in black and white, you need a converted copy.