Whiten grey, yellowed, or shadowy scanned-page backgrounds while keeping text sharp. 100% private — processed locally, no uploads, no signup.
Does your scanned PDF look grey, yellowed, or shadowy instead of clean white? That's usually uneven lighting or aged paper baked directly into the image when it was scanned — not something you can fix by adjusting brightness in a PDF viewer, because the discoloration is part of the picture itself. PDFree's Clean Scan tool corrects it: it analyzes each page's own lighting pattern, flattens the background to pure white, and keeps your text sharp and dark — entirely inside your browser, with nothing uploaded.
Click Choose files or drag your PDF into the drop zone. A live before/after preview of the page loads instantly in your browser — the file is never sent to any server.
Choose Clean for text-heavy pages — it flattens the background to pure white. Choose Enhance for pages with stamps, signatures, or photos — it brightens the page without fully whitening it. Drag the strength slider and watch the before/after preview update live.
Click Clean & Download. Every page is processed and rebuilt at your chosen quality, ready to download instantly — no waiting, no email, no account.
Many quick fixes for a grey scan amount to a single global brightness or contrast slider — fine when a page is evenly lit, and a muddy or blown-out mess when it isn't. Real scanned pages, especially from books, are rarely evenly lit: the gutter near the spine is darker, the outer edge is lighter, and a flat adjustment either leaves the dark side grey or blows the light side out to nothing. Clean Scan estimates each page's own lighting pattern first, then flattens it — so a page that's dark on one side and light on the other comes out uniformly white on both sides, with the text preserved in between.
The curve of a book's spine casts a shadow that a flatbed scanner can't avoid. Clean Scan flattens that shadow instead of leaving half the page grey.
Aged documents scan with a yellow or beige cast baked into the image. Whiten the background while keeping faded text legible.
Each generation of copying adds noise and grey. Clean it up before archiving, printing, or sharing a document that's been copied one too many times.
A clean, high-contrast background makes text recognition more reliable and produces a more professional-looking archival copy.
| Feature | PDFree | Typical cloud tools |
|---|---|---|
| File privacy | No upload — stays on device | Uploaded to remote servers |
| Account required | Never | Often after one free file |
| Page count / file size limit | None | Often capped on free tier |
| Live before/after preview | Included | Often not available |
| Price | Free forever | Free with limits / paid plans |
Reflects typical free-tier policies among popular cloud-based PDF services; individual providers' terms vary and change over time.
No. Every page is analyzed and rebuilt entirely in your browser. Your file is never sent anywhere.
Clean flattens the background to pure white and darkens text for maximum contrast — best for plain text pages. Enhance brightens the page and boosts contrast without fully whitening the background, which keeps stamps, signatures, and photos on the page recognizable.
Clean mode can fade or remove color content, since it's designed to push everything toward black text on a white background. If a page contains color you want to keep, use Enhance mode instead — the tool warns you automatically when it detects color on the page you're previewing.
Flatbed scanners and phone cameras rarely light a page perfectly evenly — a book's spine casts a shadow near the gutter, ambient light falls off toward the edges, and aged paper reflects light unevenly. That unevenness gets captured as part of the image itself, which is exactly what Clean Scan's background analysis is built to correct.
No. There's no page-count or file-size limit, and no per-hour task limit. Clean a single-page scan or a hundred-page document as often as you need.
Clean mode saves pages as PNG, which avoids the compression artifacts that would blur sharp black-and-white text. Enhance mode saves as high-quality JPEG, appropriate for pages that still contain photos or continuous-tone content.
You can, but it isn't the intended use — cleaning converts each page into an image, so real selectable text in a normal digital PDF would become a picture of text. The tool detects when a PDF looks like it has real text content and shows a warning before you process it.
Yes. PDFree works in mobile Safari (iOS) and Chrome for Android — the same mode, strength, and preview controls work with a tap.
Yes. PDFree is free with no subscription, no daily or hourly limits, and no signup. No watermark is added to the output and there's no file size restriction.
PDFree is a free online scan cleaner — whiten grey, yellowed, or shadowy scanned backgrounds with no signup, no account, and no installation. Unlike server-based tools, PDFree processes your PDF instantly inside your browser — your file never leaves your device. There are no hourly or daily limits, no watermarks added, and no file size restrictions. It works on Windows, Mac, Linux, iOS, and Android.