Grayscale PDF converter

Convert colours rewrites the PDF's colour operators in place, so text stays selectable and vector shapes stay sharp. It cannot do the impossible though: ICC and CMYK colours go through plain grey formulas instead of their colour profiles, and spot colour, indexed colour, patterns, gradients, embedded images, annotations, and form fields keep their original colour. The findings list above names anything it left behind, so check the preview before you ship the file.

Rasterise pages draws every page as a grey picture, so images and gradients go grey too, but text stops being selectable and the file usually grows. Password-protected PDFs are refused. Everything runs in this browser tab; nothing is uploaded.