Invert PDF Colours
Pixel-level inversion · 100% on-device
Drop your PDF here
or click to browse
Dark Mode PDF
Black background, white text. Kinder to your eyes at night and to OLED screens.
Three Modes
Full invert, grayscale invert, or hue-rotated invert — pick the one that reads best.
100% Private
Everything runs in your browser. Your PDF never leaves your device.
Free Forever
No signup, no watermark, no page limits, no PDFNinja branding.
How to Invert PDF Colours
Upload your PDF
Drop the file or click to browse. It stays on your device.
Pick a mode
Full invert for classic dark mode, grayscale for less colour noise, or hue shift.
Tune resolution
Higher DPI = sharper text, larger file. 150 DPI is the sweet spot.
Download
Every page is inverted and saved as a new PDF.
Frequently Asked Questions
Will the text stay selectable?
No. Inversion works by rasterising each page, flipping pixels, and re-embedding. The result is a visually inverted PDF, but text becomes part of the image. Use this for reading and printing, not for editing.
Why not invert the underlying colours in the stream?
PDF colour operators are scattered across content streams, images, fonts, and shading dictionaries. Rasterising once produces a reliable, predictable result on any PDF — including scans and image-only files.
Is my file uploaded anywhere?
No. Rendering, inversion, and re-embedding all run in your browser via WebAssembly.
What DPI should I pick?
150 DPI matches typical screen viewing and prints. Bump to 200-300 if your PDF is text-heavy and you want crisper glyphs.
Does it work on scanned PDFs?
Yes. Scans work especially well — dark scans become light, light scans become dark.