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.

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

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.

Free · No sign-up · Runs in your browserLast updated: 2026-10-26

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How to use PDF Dark Mode

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

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.