About the Grayscale PDF
Tezmy's Grayscale PDF makes a grey copy of a colour PDF, so it prints without touching the colour cartridges and looks the same on any printer. Pick your PDF, choose Grey or High contrast and a quality of 150, 200 or 300 dpi, and download the new file. Each page is drawn by your browser, turned grey and put back together as a new PDF of the same page size. Your file isn't uploaded. One honest catch: because the pages become pictures, the text in the new PDF can't be selected or searched.
Updated September 2026
How to use the Grayscale PDF
- 1Tap Select PDF file and choose your colour PDF.
- 2Pick Grey, or High contrast for text documents and scans.
- 3Choose 150, 200 or 300 dpi.
- 4Tap Make black and white PDF, then Download PDF.
Why print in black and white
Printing a colour PDF on a home or office printer can use the colour cartridges even when the page looks mostly black and grey: logos, coloured headings, highlighted table rows and photos all pull from them. A copy with no colour at all prints with black only, which costs less and still works when a colour cartridge runs dry.
It's also handy when a school, office or print shop asks for black and white files, or when you want to see how a coloured chart will look on a black and white printer before handing it out.
Choosing the look and quality
- Grey: every colour becomes the matching shade of grey. Best for photos, slides, brochures and charts.
- High contrast: very pale greys (such as tinted backgrounds or the yellow of old paper in scans) become white and dark greys become black. Best for letters, forms, receipts and scanned documents, and it uses less toner.
- 150 dpi: sharp enough for normal printing and keeps the file smaller. A good default.
- 200 dpi: a bit crisper for small text.
- 300 dpi: print-shop quality for tiny text and fine lines, but the file is several times bigger and long PDFs take longer.
What changes in the new PDF
The pages keep their size and order, and the result looks the same as the original apart from the colour. But the new file is made of pictures of the pages: the text can't be selected, copied or searched, links stop working and form fields are no longer fillable. That's the price of guaranteeing there's no colour left anywhere in the file.
The file is often bigger than a PDF made on a computer, and sometimes smaller than a colour scan. The page shows both sizes when it's done. If it's too big to email or upload, Compress PDF will shrink it.
Long PDFs and phones
Pages are converted one at a time and the button shows which page it's on. A few pages take seconds; a hundred-page PDF at 300 dpi can take a few minutes and a lot of memory, which older phones may struggle with. On a phone, pick 150 dpi for long files, or split a very long PDF into parts first with Split PDF and join the results with Merge PDF.
Features
- Grey or high-contrast black and white
- 150, 200 or 300 dpi
- Same page sizes and order as the original
- Shows the old and new file size
- Private: your PDF never leaves your device
- Works on phones and computers
Frequently asked questions
How do I convert a PDF to black and white?
Select the PDF, choose Grey or High contrast, then tap Make black and white PDF. When it says Done, tap Download PDF. Every page is converted, keeping its size and order.
Will I still be able to select and copy the text?
No. Each page is turned into a grey picture, so the text becomes part of the image. Keep your original PDF if you need to copy or search the text. If you need a searchable file later, PDF OCR can read the text back from the pictures.
Does a grayscale PDF really save ink?
Colour printers often mix colour inks even for greys and dark text. A PDF with no colour in it at all lets the printer use only black, which is cheaper, and it also avoids surprises when a colour cartridge is empty.
Grey or High contrast: which should I pick?
Grey keeps every shade, which suits photos, charts and slides. High contrast makes pale backgrounds white and dark greys black, which gives crisper text and less toner on forms, letters, receipts and scanned pages.
Why is the black and white PDF bigger than the original?
PDFs made on a computer store text very compactly. Once the pages are pictures they take more space, especially at 300 dpi. Choose 150 dpi for a smaller file, or run the result through Compress PDF.
Is my PDF uploaded?
No. Your browser reads, draws and rebuilds the pages on your own device. Nothing is sent to a server.
Can I convert a password-protected PDF?
Not directly. Remove the password first with Unlock PDF (you need to know it), then convert the unlocked copy.