Guide
Reading PDFs in dark mode, on any device
Long reading sessions on a bright white page are tiring, especially at night or on a phone in a dark room. Many apps have a dark mode, but PDFs mostly don’t: some readers can invert pages, many can’t, and the setting doesn’t travel with the file. A dark copy of the PDF looks the same in every reader, on every device, including e-readers and tablets that have no dark option for PDFs.
Dark mode or negative?
Dark mode (keeps colors) flips how light each color is, while keeping what color it is. White paper becomes dark, black text becomes light, and colored elements stay recognisable: a red warning stays red, a blue link stays blue, green chart lines stay green. This is what most people mean by dark mode.
Negative turns every color into its opposite, as on photographic film. Black and white swap just the same, but red becomes cyan and blue becomes orange. It’s useful for line drawings, plans and scanned sketches, or when you want the classic inverted look.
The preview of page 1 updates as you switch, so compare both on your own document.
Soft or pure black
With Soft dark gray on, the background is a very dark gray and text is an off-white, rather than pure black and white. The contrast is still high but less glaring, which many people find easier for long reading. Turn it off for pure black, which saves the most battery on OLED phones and looks crisp on e-ink devices.
Text stays searchable
The dark pages are images, which by themselves would lose the ability to search and copy text. With Keep the text searchable on, each dark image is laid over the original page. You see the dark version; search, text selection, copying and read-aloud still use the original text underneath. The file gets larger because it contains both. Turn the option off for the smallest file.
Quality
- Smaller file (100 DPI): fine for phones.
- Balanced (150 DPI): sharp on most screens, the default.
- Sharp (220 DPI): for tablets and zooming into small print.
Good candidates for a dark copy
- research papers and e-books read in the evening,
- manuals and documentation kept open next to code,
- sheet music or scripts read on a stand under low light,
- slide decks reviewed on a phone.
Documents full of photos are less suitable: photos are inverted too, which keeps shapes visible but makes people and scenes look strange.
Printing
Don’t print the dark copy. It uses a huge amount of ink or toner. Keep the original for printing, or use Grayscale PDF for an ink-saving black-and-white print.
Related tools
For a tinted background such as sepia or cream instead of dark mode, use Change PDF Colors. If the dark PDF is large, reduce it with Compress PDF. Everything runs in your browser; the document is not uploaded.
A worked example: an e-book for night reading
A reader wants a dark copy of a 300-page novel for their phone.
- Open the PDF; the preview shows page 1 in dark mode with soft gray.
- Choose Smaller file, since the phone screen is small, and keep the text searchable so passages can still be found with search.
- Create the dark PDF and copy it to the phone.
Checked against the current version of the Invert PDF Colors on .