How to convert a PDF to grayscale with OnyxPDF
- Drop your PDF into the tool.
- Click “Convert to Grayscale”.
- Download the black-and-white PDF from the output list.
Why do it in your browser instead of uploading?
- Print savings: a grayscale document can be printed on the cheap black cartridge instead of colour.
- Often smaller files, since colour data is discarded.
- No upload — convert internal documents locally.
- Free and unlimited.
Good to know (honest limits)
- Pages are re-rendered as images during conversion, so text in the output is not selectable — keep the original if you need the text layer.
- Colour is discarded permanently in the output; there is no “undo colour” — again, keep the original.
Frequently asked questions
Why convert a PDF to grayscale?
Mainly for printing economics (black ink only), a uniform look for scanned documents, and sometimes a smaller file.
Will the text stay selectable?
No. Conversion renders pages as images. If you need selectable text, keep using the original file.
Will the file get smaller?
Usually, yes — dropping two colour channels saves space, though the amount varies with content.
Is my file uploaded?
No. Conversion runs entirely in your browser.