Each page is rendered and converted to gray. This rasterizes pages, so selectable text becomes part of the image.
How to convert a PDF to grayscale
- Add your PDF to the panel.
- Choose a resolution: 110, 144, or 200 DPI.
- Click the button and download the grayscale PDF.
When to convert a PDF to grayscale
Grayscale conversion is the standard way to prepare a document for black-and-white printing, cutting toner cost on color-heavy pages.
It also gives documents a clean, uniform look, and it usually shrinks the file: removing color data from scans and image-heavy PDFs often reduces size noticeably.
Why convert PDFs to grayscale in your browser
The conversion runs on your device with no upload and no account, so the document stays private.
Free in the browser on any device. The PDF Shrink iPhone app offers the same local conversion offline.
FAQ
Does grayscale shrink the file?
Often, yes. Removing color usually reduces size, especially for scans and image-heavy PDFs.
Does it keep text selectable?
Pages are rendered and converted, which rasterizes them. Text becomes part of the image, so use the text-based Optimize compression if you need selectable text.
Which resolution should I pick?
144 DPI is a good default for screen and print. Use 200 for sharper output, 110 for smaller files.
Is the original file changed?
No. The grayscale result is a new file.