Invert PDF ColorsWithout Breaking Your Images
Flip a PDF to a dark background in seconds — but keep photos, charts, and diagrams in their original color. Runs entirely in your browser. No upload, no signup.
Why regular “invert colors” breaks your PDFs
Most invert tools flip every pixel. That works for text but ruins everything else.
- Sky turns orange
- Skin turns blue
- Charts with colored backgrounds get mangled
- Logos look like negatives of themselves
- Scanned signatures become illegible
- Detects images by pixel saturation before inverting
- Text + diagrams get the dark treatment
- Photos and color figures stay untouched
- Four themes: Midnight / Sepia / Solarized / OLED
- No trial-and-error — the result just looks right
The saturation threshold is tuned to catch photos (high color variation) while converting monochrome content (low color variation). See our home page for a comparison against Chrome extensions and other tools.
When you'd want to invert PDF colors
White PDF backgrounds are painful in a dimly-lit room. Invert once, save the output, and keep that copy for any time you need to read after sunset.
Black pixels are literally “off” on OLED and save power. Pick the OLED theme for pure blacks — brighter text, better battery, deeper contrast.
High-contrast light-on-dark is easier for many readers with astigmatism, migraine sensitivity, or low vision. Produces a persistent, shareable file — not just a setting someone has to rediscover every time.
Unlike an OS-level invert toggle, the inverted PDF is a real file you can email, AirDrop, or upload anywhere. The recipient sees the dark version in every viewer.
FAQ
What does 'invert PDF colors' actually do?
It flips each pixel's color to its opposite — black becomes white, dark grey becomes light grey, and so on. The result is a PDF with a dark background and light text, which is easier on the eyes at night.
Why do my photos look weird after inverting a PDF?
Naive color inversion is applied to every pixel — including images. Photos become negatives (skies turn orange, skin turns blue), and charts with colored backgrounds get mangled. PDF Dark avoids this by detecting image regions via pixel saturation and leaving them alone.
Is this reversible? Can I go back to the original?
Yes — the conversion produces a new PDF. Your original file is never modified. Keep both if you want.
Can I invert colors for a specific page only?
Not yet — the inverter runs on the whole document. If you need per-page control, open the PDF in a desktop editor like PDF Expert after converting.
Does this work on scanned PDFs?
Yes — scanned pages are just images inside a PDF, and our algorithm treats them the same way. Handwriting and typed text become light-on-dark automatically.
Is my PDF uploaded anywhere?
No. The inversion runs entirely in your browser via the File API and a Web Worker. You can verify this by opening DevTools → Network — there is no upload request for the file.