ClientPDF
running locally in this tab — nothing uploaded

Open DevTools.
Convert colored text and graphics to grayscale.
Watch nothing get sent anywhere.

Rewrites the RGB and CMYK color operators in a PDF's text and vector graphics to grayscale using the standard luminosity formula. All inside this tab. Zero network requests after the page loads, same rule as every other tool here. Check the Network tab yourself.

Drop one PDF here or click to browse

One file at a time · stays on this device

    Why trust this tool

    0 network requests since page load · verified live, not our word for it

    No accounts

    No signup, no email, no watermark. Use it and close the tab.

    No limits (for now)

    Convert as many pages as your device's memory allows. No artificial caps.

    Resizing pages or cropping margins too? Both live too.

    Rescale every page to a standard size or percentage, trim margins without rescaling content, or shrink the file size — same rule: everything stays local. Leave your email and we'll let you know about a Pro batch mode.

    Converting drawing instructions, not pixels

    Grayscale PDF rewrites the RGB/CMYK color-setting operators inside each page's own content stream (rg, RG, k, K) to their grayscale equivalents using the standard luminosity formula, decoding each stream, regex-rewriting the color values on token boundaries, and writing it back — a genuinely different code path from every other tool here, since it edits drawing instructions rather than page structure or embedded assets.

    That also means it's honest about its limits: pattern, Separation, and ICC-based color spaces, plus any embedded raster images, are intentionally left untouched rather than guessed at — so a scanned page that's really just one big colored image won't visibly change here, only vector graphics and text-drawing colors will. If that's what you need converted, this isn't the right tool for it yet. As with the other tools, a locked PDF can't be processed at all — here's why password-protected files don't open here.