Grayscale PDF
Convert a colour PDF to black and white for cheaper printing — it usually shrinks the file too.
Grayscale PDF online, free and private
Converting a PDF to grayscale turns every page black and white — the classic reasons being cheaper printing (colour ink and colour-page charges add up fast), print shops that require grayscale submissions, and cleaner photocopies. As a side effect, grayscale conversion usually shrinks the file too, since colour information is discarded.
PDFToolz renders each page in your browser, converts the pixels to true grayscale using the standard luminance formula, and rebuilds the PDF around the converted pages. You choose the quality level, and — as with every tool here — the document is never uploaded.
How to grayscale pdf in your browser
- 1
Add your PDF
Click ‘Select PDF file’ or drop the document onto the page.
- 2
Pick a quality level
‘Recommended’ keeps text crisp at a sensible file size; choose ‘High quality’ for print-shop output or ‘Smaller file’ when the result needs to be emailed.
- 3
Convert and download
Press ‘Convert to grayscale’. Every page is re-rendered in black and white and the converted PDF downloads when the last page finishes.
Why use PDFToolz for this
True grayscale, not washed-out colour
Each pixel is converted with the ITU-R luminance formula that weights red, green and blue the way human vision does, so photos keep their contrast and text stays fully black.
Usually smaller files
Discarding colour data and re-encoding the pages typically shrinks the PDF noticeably — handy when a colour-heavy report needs to squeeze under an email attachment limit.
Your files stay private
The conversion runs entirely in client-side JavaScript. Your document is never sent to a server, cached, or stored anywhere but your device.
Free with no limits
Convert as many PDFs as you like — no account, no watermark, no page caps.