# PDF Dark Mode - Convert PDF to Dark Theme or Night Reading Colors Online

> Free online PDF dark mode converter: turn black-on-white PDFs into light-on-dark pages, with hue-preserving, sepia or custom colours. Text stays selectable.

- URL: https://qilingtools.com/en/pdf/dark-mode
- Category: PDF Tools (https://qilingtools.com/en/pdf)
- Tags: [PDF](https://qilingtools.com/en/tags/pdf), [Documents](https://qilingtools.com/en/tags/document)
- Last updated: 2026-10-26
- Price: Free, no sign-up
- Privacy: Runs locally in the browser; files are never uploaded

Reading papers, novels and manuals at night on a tablet, e-reader or phone, a white PDF page is glaring, and many readers either have no dark mode or do it badly. This tool creates a dark copy of the PDF that shows light text on a dark background in any reader. The recommended Smart dark mode inverts the page and then rotates the hue by 180 degrees, so white paper becomes dark grey and black text becomes light while red headings and blue charts keep their colour; it also finds the photos on each page and paints them back in their original colours, so pictures never look like film negatives. Full invert simply flips every pixel. If you prefer something softer, choose Sepia reading or set your own background and text colours under Custom (presets include dark grey, navy, terminal green and eye-care green). Every change is previewed live on page 1 next to the original. Because the colours change, pages are rendered as images at 100–300 DPI; with “Keep text searchable” enabled, an invisible text layer is added underneath so you can still search, select and copy. Everything happens locally in your browser with no upload.

## How to use

1. Upload the PDF you want to convert
2. Pick a theme (Smart dark, Full invert, Sepia or Custom colours), decide whether photos stay natural, and check the live preview of page 1
3. Choose resolution and quality, then click Convert & download to get the dark PDF

## Features

- Smart dark: inverted brightness with the original hues
- Photos detected and kept in their natural colours
- Full invert, sepia and custom colour themes
- Presets: dark grey, navy, terminal green, eye-care green
- Invisible text layer keeps text searchable and copyable
- Live side-by-side preview of page 1
- 100–300 DPI output, processed locally

## FAQ

### What is the difference between Smart dark and Full invert?

Full invert flips every pixel, so red turns cyan and photos look like negatives. Smart dark inverts and then rotates the hue by 180 degrees, so reds stay red and blues stay blue with only the brightness reversed, and photo areas are restored from the original page for a natural look.

### Can I still search and copy the text?

Yes. With “Keep text searchable and selectable” (on by default), the text of the original PDF is added as an invisible layer at the same positions, so searching, selecting and copying work in any reader. Scanned PDFs have no text to keep; run Scanned PDF OCR first.

### Why is the new file bigger?

Changing the colours requires rendering each page as an image, which is usually larger than a text-based PDF. Lowering the resolution to 100–150 DPI and reducing the quality shrinks it considerably; 150 DPI is plenty for phones and tablets.

### Are my files uploaded?

No. Rendering, recolouring and building the new PDF all happen in your browser with no network upload.

## Related tools

- [Merge PDF](https://qilingtools.com/en/pdf/merge): Free online PDF merger: combine several PDF files into one in the order you choose, with reordering. Processed locally in your browser, no upload, no sign-up.
- [Split / Extract PDF](https://qilingtools.com/en/pdf/split): Free online PDF splitter: extract a page range into a new PDF, or split every page into its own file and download them as a ZIP. Processed locally.
- [Rotate PDF](https://qilingtools.com/en/pdf/rotate): Free online PDF rotator: rotate all or selected pages by 90°, 180° or 270° to fix scanned documents. Processed locally, no upload.
- [PDF to Image](https://qilingtools.com/en/pdf/to-image): Free online PDF to image converter: render every page as a high-resolution JPG or PNG at 72/150/300 DPI, download all as a ZIP. Processed locally, no upload.
- [Image to PDF](https://qilingtools.com/en/pdf/from-image): Free online image to PDF converter: combine JPG, PNG and WebP images into one PDF in order, with A4 or image-sized pages. Processed locally, no upload.
- [Compress PDF](https://qilingtools.com/en/pdf/compress): Free online PDF compressor: re-render pages with compressed images to shrink scanned and image-heavy PDFs, with adjustable quality. Processed locally.
- [Watermark PDF](https://qilingtools.com/en/pdf/watermark): Free online PDF watermark tool: add text watermarks to every page, tiled or centred, with opacity and angle controls. Any language, processed locally.
- [Delete PDF Pages](https://qilingtools.com/en/pdf/delete): Free online tool to delete PDF pages: remove pages by number or range and keep the rest, then download. Processed locally, no upload.