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HomePDFScan to PDF

Scan to PDF

Scan documents with your camera into a PDF. Free, private, runs in your browser.

100% private — your files never leave your browser. All processing happens locally on your device.

Scan documents to PDF

Use your phone camera or upload images. 100% private — nothing leaves your browser.

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What Is Scan to PDF?

Scan to PDF turns your phone or computer's camera into a document scanner. Capture a printed page, drag the corners to crop, apply a filter to clean up the image, then export as a multi-page PDF — all in your browser. No app install, no upload, no account.

Why Use a Browser Scanner Instead of an App?

Native scanner apps like Adobe Scan and CamScanner are powerful, but they push your documents through their servers and bury features behind subscriptions or watermarks. Convertful runs the entire scanning pipeline locally — perspective correction, filtering, multi-page assembly, and PDF export all happen in JavaScript and WebAssembly inside your browser tab. Your documents never travel over the network. There's no signup, no daily limit, no premium tier. Open the page, scan, save the PDF, close the tab — that's it.

How Does Edge Detection and Flattening Work?

When you confirm a capture, the tool reads the four corners you've placed on the captured frame and computes a perspective homography that maps the distorted quadrilateral onto a clean axis-aligned rectangle. It then bilinearly samples the source image to produce a flat, undistorted page — the same math that makes Adobe Scan's output look square even when you photographed the page from an angle. Phase 2 will add automatic edge detection so you don't have to drag the corners manually.

Which Filter Should You Use?

Color preserves the original capture — best for photos and full-colour pages. Auto applies a contrast stretch and slight saturation boost — a good default for most documents. Grayscale strips colour for smaller files and a classic scanner look. B&W (black and white) uses an adaptive Sauvola threshold that handles uneven lighting much better than a global threshold — ideal for text-heavy pages where you want crisp, OCR-friendly output even if the lighting was uneven.

Is It Safe and Private?

Yes. Every step happens in your browser. The camera stream is consumed locally by the canvas API and never sent anywhere. Captured frames live in memory only. Filtering and PDF assembly run in your tab via pdf-lib. The downloaded PDF is generated client-side and saved directly to your device. Convertful has zero access to your scans — ideal for confidential paperwork, receipts, IDs, contracts, and anything else you'd rather not hand to a cloud scanning service.

FAQ

Does it work on mobile?

Yes — designed mobile-first. Tap Open Camera to scan with your phone's rear camera, then drag the corners to crop the page.

Are my documents uploaded anywhere?

No. Every step — capture, perspective correction, filtering, and PDF assembly — runs in your browser. Files never leave your device.

Can I scan multiple pages?

Yes. After confirming each capture, tap Add Page to capture more. Reorder, retake, or delete pages from the review screen before saving.

Which filter should I use?

Auto for most documents (boosts contrast, keeps colour). B&W for text-heavy pages — uses adaptive thresholding so it stays legible under uneven lighting. Grayscale for photos or receipts. Color preserves the original.