How to make a PDF grayscale
- Choose your PDF.
- Pick a method. For the picture methods, also set the resolution and quality.
- Press Convert, compare the before and after pages, and download.
Black and white uses a cut-off: anything lighter becomes white and anything darker becomes black. Raise the cut-off if thin text looks faint.
Questions
Is my PDF uploaded?
No. The conversion runs in your browser and the file never leaves your device.
Which method should I choose?
Sharp text is best when you only want gray output: text stays selectable and crisp. Gray image and Black & white turn every page into a picture, which can make scanned or photo-heavy files smaller.
Will the file get smaller?
Not with Sharp text, because the original colors stay inside the file. The Gray image and Black & white methods often shrink the file, especially black and white. The result shows the size before and after.
What resolution should I use?
150 dpi is fine for reading and most office printing. Use 300 dpi for fine print or photos you want to print. Lower numbers give smaller files.
Does it save ink?
It stops color ink from being used for color content, which many printers need anyway to print in gray. Most printers also have their own “print in grayscale” setting.
Credits
Built on pdf-lib (MIT) and PDF.js (Apache-2.0). OneTooling is not affiliated with these projects.