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Convert PDFs to grayscale.

Color PDFs turned print-ready grayscale — all in-browser.

No uploads — 100% local No ads Free & open source

Drop PDF files here

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Files never leave your device. Everything runs in your browser, nothing touches a server — tools you've used even work offline.

Convert a color PDF to grayscale entirely in your browser — every image, graphic and text color mapped to clean mono by Ghostscript, locally. Ideal before ink-friendly printing, for consistent handouts, and often smaller files too.

How it works

  1. Drop files anywhere on the page, click to browse, or paste with ⌘V.
  2. Pick a quality or preset — or set an exact target size and let the tool find it.
  3. Compress, compare before/after, and download — individually or as a ZIP.

Why go grayscale

Printing color documents on a mono printer produces muddy, inconsistent grays — converting first gives the printer exactly what it will print. Grayscale images also compress tighter, so colorful decks often shrink along the way; run Compress PDF after for the full squeeze. The conversion re-serializes the document through the same Ghostscript engine the compressor uses.

What converts to what

Grayscale keeps brightness and discards hue — which is fine for most content and a real trap for one kind: colors chosen to differ only in hue. A red line and a green line of equal brightness become the same gray.

If a chart leans on a color legend, check that page in the output — and consider re-labeling the series before converting.

ContentIn grayscale
PhotographsSmooth, natural tones — the classic black-and-white look
Charts with same-brightness colorsSeries can merge into one gray — the case to check
Text and vector linesRecolored, never rasterized — stays perfectly sharp
Colored highlights and fillsLight gray shading; contrast against text usually survives

Frequently asked questions

Does grayscale make the file smaller?

Usually — a grayscale image stores a third of the color data. Decks full of colorful graphics shrink noticeably; text-only documents barely change.

Is the conversion reversible?

No — color information is discarded in the output. Keep your original file; it is never modified.

Will text stay sharp?

Yes — text and vector graphics are recolored, not rasterized. Images are converted pixel-for-pixel without downsampling.

Is it private?

Yes. The document never leaves your browser — nothing is uploaded, and the server only delivers this page. That makes it safe for contracts, invoices, medical records — anything you would not email to a stranger. Want proof? Run one file through, switch your connection off, and run another — it still works.