Grayscale PDF

No upload · runs in your browser

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Runs entirely in your browser, nothing is uploaded.

How it works

Grayscale PDF : Convert Colour Pages to Black and White

Turns a colour PDF grey at 96, 150, 200 or 300 DPI, using Rec. 709 luminance so reds and blues keep their contrast instead of flattening.

What this does

Rec. 709 luminance weights, 0.2126 red, 0.7152 green, 0.0722 blue
96, 150, 200 or 300 DPI, with the longest canvas edge capped at 4,500 px
Before and after file sizes reported per run, with the percentage change
Rendered by pdf.js and rebuilt by pdf-lib in this tab; no request carries the file

FAQ

No, and this is the trade-off to weigh before running it. Each page is rasterised, converted to grey pixel by pixel and re-embedded as a JPEG at 85% quality, which flattens text, links, form fields and annotations into a single flat image. For a print or filing copy that is often exactly what you want, nobody can edit it and nothing reflows. If you need searchable text afterwards you have to put it back with OCR, so keep the colour original.

150 DPI is the sensible default for office printing. Drop to 96 DPI for something that only ever gets read on screen, and go to 300 DPI when fine print or a scanned signature has to stay crisp. Higher DPI always means a bigger file, and a text-only PDF can come out larger than the original at 300 DPI because sharp vector text is being replaced by a raster image. Very large pages have their render capped at 4,500 px on the longest edge, and the summary says “capped” when that happens.

Keep going

Bates Numbering

Compress PDF to Size

Extract PDF Pages

Extract Images from PDF

Markdown to PDF

PDF Metadata Editor