Invert the colours in a PDF
Turn a white document dark, so it is readable at night on any device.
Or drop one anywhere on this page
What to know about Invert PDF Colours
Turn a glaring white document into a dark one, saved into the file itself so it looks the same in every reader and on every device. The default keeps hues where they are, so a blue link stays blue rather than turning orange. The conversion runs on your own device.
Reading a white page on a screen in a dark room is unpleasant, and every PDF reader knows it — which is why they all have a night mode. Those night modes are display settings. They live in one application on one device, and they travel with neither the file nor the person reading it. The moment the document goes to an e-reader, onto a tablet you do not control, or to somebody else, the setting is gone.
So this writes the change into the document. What comes out is a dark PDF, and every reader on every device shows it dark, because there is nothing left to interpret.
The two modes are worth understanding before you pick one, because choosing wrongly is immediately obvious. Full invert does what the word means: each colour is replaced by its opposite, so white becomes black and black becomes white. On a page of plain black text that is exactly right. On anything with colour in it, it is destructive in a way that is easy to underestimate — inversion rotates hue as well as lightness, so a blue hyperlink comes out orange, a red warning comes out cyan, and a company logo comes out in colours nobody chose.
Dark mode inverts lightness only. Hue and saturation are left where they were, so the page goes near-black and the text near-white while a blue link stays recognisably blue. It costs a conversion into and out of a different colour representation for every pixel, which is why it is not the only mode offered, but it is the one most real documents want and it is the default.
There is a real cost, and it is the same one redaction pays. Colour in a PDF is not a single property that can be changed: it comes from operators scattered through each page's content stream, from inside every embedded image, and sometimes from a colour profile attached to the whole file. There is no reliable way to rewrite all of that — an attempt leaves some elements inverted and others untouched, which looks worse than not trying. So each page is rendered to pixels, the pixels are inverted, and the result replaces the page. The text stops being selectable and searchable, and the file grows.
Pages are stored as PNG rather than JPEG, which is a small decision with a visible effect. JPEG's compression artefacts cluster around sharp edges; on a white page with black text they are essentially invisible, and on a dark page with light text they are a grey halo around every letter. PNG costs more bytes and produces text you can actually read.
The case where all of this is unambiguously worth it is a scan. A scanned page is already an image, so there is no text layer to lose — and it is exactly the case where a reader's own night mode does nothing at all, because those modes invert text and leave images alone.
How to invert the colours in a PDF
- 1
Bring in the document
Choose the PDF or drop it onto this page. Nothing is uploaded to be read.
- 2
Choose how much to invert
Dark mode inverts lightness and keeps hues, so coloured text and logos survive. Full invert flips every channel, which suits plain black on white.
- 3
Pick a quality
Standard is fine on screen. High renders at 300 DPI for small type, at a larger file.
- 4
Convert and download
Every page is rebuilt with the new colours and the finished file downloads straight to you.
What Invert PDF Colours accepts and produces
- Input
- One PDF, and a choice of how much of the colour to invert.
- Output
- The same pages with their colours inverted, saved into the document.
- Limits
- Pages are rebuilt from pixels, so text stops being selectable and searchable and the file gets larger. This is the trade for an inversion that is in the file rather than applied by one reader's night mode.
- Offline
- Yes, once the rendering engine has been fetched on your first visit.
Why Invert PDF Colours here
- The inversion is in the file, so every reader and every device shows it
- Dark mode keeps hues, so links stay blue and warnings stay red
- Works on scans, where a reader's night mode usually does nothing
- Pages are rendered as PNG, so light text on dark stays sharp
- Nothing is uploaded — the whole conversion runs in your browser
Where your file goes
Nowhere. This tool runs inside your browser, and the page is served with a policy that forbids it from sending your document anywhere. You can confirm that yourself: open your browser’s developer tools, watch the Network tab, and process a file.
Questions
Why not just use my PDF reader's night mode?
Use it, if the document is only ever going to be read there. A reader's night mode is a display setting: it lives on that device, in that application, and travels with neither the file nor you. This writes the change into the document, which is what you want when it is going to an e-reader, onto a tablet you do not control, or to somebody else. It also works where night modes commonly fail — on a scanned page, which is a picture, so many readers refuse to invert it at all.
What is the difference between dark mode and full invert?
Full invert replaces each colour with its opposite: white becomes black, and blue becomes orange. It is exactly right for a page of black text on white, and it wrecks anything with colour in it. Dark mode inverts only lightness, leaving hue and saturation alone — the page goes near-black and the text near-white, but a blue hyperlink is still blue and a red warning is still red. That is the one most documents want, so it is the default.
Why does the text stop being selectable?
Because the colours in a PDF are not one setting that can be changed. They come from colour operators scattered through each page's content stream, from inside embedded images, and sometimes from an ICC profile attached to the file. Rewriting all of those correctly is not possible in general, and a tool that tried would leave some elements inverted and others not. Rendering the page and inverting the pixels is the approach that works on every document, and the price is that the page becomes an image.
Will the file get bigger?
Usually yes, sometimes considerably. A text page is a very compact thing — a few kilobytes of instructions — and a picture of that page is not. Pages are stored as PNG rather than JPEG because JPEG's ringing artefacts sit invisibly around dark text on a white page and very visibly around light text on a dark one. Run the result through Compress PDF if the size becomes a problem.
Can I invert it back afterwards?
Running a full invert twice returns the original colours, though not the original file — the text layer was lost the first time and does not come back. Dark mode is not exactly reversible, because inverting lightness twice does not return every pixel to precisely where it started. Keep your original either way; that is true of every tool here that rebuilds pages.
Does inverting work on a scan?
Yes, and this is where it is most useful. A scan is already a picture, so there is no text layer to lose and nothing is given up by rebuilding it. It is also the case most reader night modes handle worst, because they invert text and leave images alone — which on a scan means they do nothing at all.
Does the document leave my device to be inverted?
It does not. Rendering, inverting and re-saving all happen in a worker inside this tab. Open your browser's network panel and convert a file — nothing carrying the document goes out, and with the network switched off it works exactly the same.
Worth reading about Invert PDF Colours
- PDF work for teachersAssembling worksheets, splitting a scanned pile of submissions, and keeping printing costs down. The PDF jobs that come up in a classroom, done quickly.
- Why a PDF prints wrongA PDF that looks right on screen and prints wrong usually has one of five specific causes. How to identify which, and what actually fixes each one.