Images, text and vector graphics come out in shades of grey, ready for cheaper black-and-white printing. The text stays selectable, and no file ever gets uploaded to a server.
100% private: everything runs on your computer, your files never leave your device.
Every image is re-encoded in shades of grey and the colours of text and vector graphics are rewritten to their grey equivalent. Nothing is rasterised, so the text stays selectable.
No. The conversion runs entirely in your browser, on your own computer. Your file never leaves your device.
Photos, text and drawings do. A few rare elements, such as colour gradients and patterns, may keep their colour.
Grey pages usually compress well, and on the same screen you can pick a compression level to reduce the size further.
Mono laser printing is cheaper and grey documents avoid colour-toner surprises; it is also how many print shops ask for drafts.