Darken PDF
Make a faded scan or light grey text darker and easier to read. The text layer, links and layout stay as they are.
Darken a PDF for free in your browser: faded scans get white paper and darker ink, and text written in light grey is made darker, so the pages are easier to read and print. The scan pictures are corrected in place, so an OCR text layer, links and bookmarks are kept, and photographs are left as they are. Nothing is uploaded. A before and after preview shows the result first, in three strengths or pure black and white.
Drop a PDF here, or browse
A faded scan, a photocopy, or a PDF with light grey text. Nothing is uploaded.
①Select file→②Convert→③Download
Private
Stays on Device
Instant
How it works
- Choose a PDF. It is opened on your device and never uploaded.
- See which pages are faded scans and which have grey text.
- Pick Light, Medium or Strong, or pure black and white, and compare before and after.
- Darken and download. The text layer, links and layout stay as they were.
When it helps
- Old photocopies and faded handouts that are hard to read on screen
- Scans with grey or yellowed paper and a dark shadow near the spine
- Notes and worksheets written in pencil or light pen
- PDFs with light grey text that prints too faint
- Receipts, faxes and forms to print or send clearly in black and white
Key Benefits:
- ✓Text Layer and Links Kept - Scans are corrected in place, so OCR text stays searchable and links still work
- ✓Nothing Uploaded - The PDF is darkened in your browser and never leaves your device
- ✓No Sign-up, No Watermark - Free, with no daily limit and nothing added to your pages
- ✓See It First - A before and after preview, photographs left alone, and every change checked against the original
Privacy First:
Your PDF is opened and darkened in your browser. It is never uploaded, so a scanned ID, contract or medical letter stays on your device.
Frequently Asked Questions
How do I darken a scanned PDF?
Open it here, choose Light, Medium or Strong, check the preview and download. Every page is done in one go, however many there are: each scanned page gets white paper and darker ink. Medium suits most faded pages; Strong turns very faint pencil and print black.
Will the text stay selectable and searchable?
Yes. The scan pictures are replaced in place and the text layer is not touched, so an OCR layer you already have stays, and text you could select or search before still can be. Before the download is offered, the result is checked against the original: the same pages and the same text.
Can it darken light grey text in a PDF that is not a scan?
Yes. Text written in a light colour is made darker and keeps its colour, so grey becomes nearly black and light blue becomes dark blue. The pages stay real text, not pictures. White text, turned watermarks and very large headings are left as they are.
Is my PDF uploaded?
No. The PDF is read and darkened in your browser, and it never leaves your device, which matters for medical letters, contracts and scanned IDs.
Will it turn a grey or yellow background white and remove the shadow near the spine?
Yes, in most cases. The paper colour is measured across each page, so grey or yellowed paper and a shadow that darkens towards one edge become white, while the text on them stays dark. White paper also prints without wasting toner.
What does pure black and white do?
Every pixel becomes black or white. Faint strokes come out black, the page prints crisply and the file usually becomes much smaller. Grey shading, colour and highlighter are lost, so it suits pages of text better than pages with photos or coloured marks.
Will it change photos, stamps or signatures?
Photographs are left as they are, and the result says how many were left. Coloured ink on a scanned page, such as a blue signature or a red stamp, stays in colour and is made darker with the rest, unless you choose pure black and white.
Why is the file size different afterwards?
Each darkened scan is saved again. A page of black text on white paper is stored as lossless grey and usually gets smaller; a page with colour is stored as a JPEG. In pure black and white it usually gets much smaller. Both sizes are shown before you download.
It still prints too light. What else can I check?
Look at the printer settings: toner or ink saving, draft quality and a light print density all make every page paler. If the darkened PDF looks dark on screen but not on paper, the printer is the cause, not the file.
Is it free? Are there limits?
Yes, it is free, with no sign-up and no watermark. A PDF locked against changes opens without a password, and one that needs a password to open asks for it. The only limit is your device's memory: scans are darkened one at a time, and a single picture larger than about 16 megapixels is left as it is.
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To make a scan searchable, run OCR on the result. If a picture is blurry rather than faded, improve its quality first.