Adjust the colours of a PDF
Make pale scans darker and clearer before printing or sharing, in your browser.
- Your files are never uploaded
- Processed on your device
- Works offline
- Free, no sign-up
Drop your PDF files here
PDF files · up to 10 files, 500 MB each
or paste with Ctrl+VLive preview
Settings
How it works
Add your PDF
Usually a scanned document.
Move the sliders
Watch the live preview.
Download
Save the clearer copy.
Clearer scans
Faded scans often look grey. More contrast makes text darker and paper whiter. Colour strength at -100 gives greyscale.
The pages become pictures.
Private
Your file is processed inside your browser with PDF.js (Apache-2.0) and pdf-lib. It is never uploaded, and nothing is saved after you close the page.
Questions
Are my files uploaded?
No. The tool runs inside your browser, so your files are opened and changed on your own device. They are never sent to us or to anyone else.
Does it work on digital PDFs?
Yes, but the pages become pictures, so text can no longer be selected.
Is it free?
Yes. Free to use, with no sign-up, no watermark and no daily limits.
Related tools
More free tools that run on your device. No uploads