Some places simply want a PDF without color: court and government portals that ask for black-and-white submissions, print shops that charge color rates the moment one page has a colored logo, and archives that store documents in grayscale. Printer settings only change one printout; this tool produces a gray PDF you can send or keep.
Choose a resolution and press Convert. Each page is rendered and converted to shades of gray inside your browser, and a new PDF with the gray pages is saved to your device. Nothing is uploaded.
What converting a PDF to grayscale does
Grayscale means every color is replaced by a shade of gray of similar brightness, from white to black. The tool uses the standard luma formula from television, which weights green most and blue least, the way the eye perceives brightness, so a red heading and a dark blue one stay distinguishable as different grays.
To guarantee that nothing colored survives, including colored text, vector charts, photos and logos, each page is redrawn as a picture. That is the important trade-off: in the new PDF every page is an image. Text can no longer be selected, copied or searched, links stop working, and bookmarks, form fields and document properties are not carried over. Keep the color original as your working copy.
When a grayscale PDF is the right choice
Submissions that must be black and white
Some e-filing systems, exam boards and visa portals reject or flag color documents. Converting the final PDF before upload takes care of logos, colored signatures and highlighted passages in one step.
Avoiding color printing charges
Copy shops and office printers often bill a page as color when it contains a single colored element. A grayscale file guarantees black-and-white pricing and shows beforehand how the printout will look.
Checking readability without color
Charts that rely on red versus green, or light colored text on tinted boxes, can become unreadable in black and white or for readers with color vision deficiency. A gray version reveals the problem before the document goes out.
Resolution, quality and file size
The pages are drawn with PDF.js, the same engine that displays PDFs in Firefox, at the Resolution you choose. 72 DPI matches screen size and gives small files suitable for viewing only. 150 DPI, the default, is sharp on screen and acceptable on paper. 300 DPI suits printing, especially of small text, but takes longer and produces larger files. Each gray page is stored as a JPEG at 85 percent quality inside a PDF with the same page sizes as the original.
Whether the result is smaller or larger than the original depends on the content. A brochure full of color photos usually shrinks, because gray images need less data. A text-only document usually grows, since compact text is replaced by an image of each page, and at 300 DPI the increase can be several times. If a page cannot be drawn completely, for example because of a damaged image, the conversion stops with an error rather than producing a page with something missing.
Как пользоваться инструментом
- Drop one or more PDFs on the box above, or click Choose files (up to 200 MB each).
- Choose the Resolution: 72 DPI for screen, 150 DPI for general use, 300 DPI for printing.
- Press Convert and wait while each page is redrawn in gray.
- Download the PDF, saved with -grayscale added to its name, or press Download all (.zip).
Limitations
- Text becomes part of a page image and cannot be selected, searched or read aloud by screen readers. An OCR program can add a text layer again if you need one.
- Links, bookmarks, working form fields and document metadata are lost. Visible comments and form answers usually survive only as part of the page image.
- Very large pages are drawn at a lower resolution than chosen, so that each page stays within the browser's canvas size limit of about 16.7 megapixels.
- Password-protected PDFs cannot be opened. Unlock them first if you are allowed to.
- Long documents at 300 DPI need time and memory, which may be too much for older phones.