Document scanner app

Free Document Scanner

A simple camera photo of paper keeps curled corners, desk clutter, and uneven shadows. Paperly's document scanner engine transforms ordinary handheld camera snapshots into crisp, publication-grade documents that look like they came straight off a flatbed scanner—all processed offline on your phone or PC.

Read the guide
Document scanner in Paperly showing automatic edge detection and crop controls

What it is

A document scanner is the core capture technology that converts raw photographs of paper into flat, high-contrast digital documents. Paperly's computer vision engine runs real-time quadrilateral boundary detection, corrects acute camera angles with perspective projection, and applies adaptive binarization to lift desk shadows and enhance text legibility completely on-device.

When you reach for it

  • The page is curled, creased, or lying on a dimly lit surface
  • Lighting is uneven and a standard photo leaves hand shadows across lines of text
  • The document must look professional for legal filings, business proposals, or official records
  • Capturing receipts, bills, and contracts rapidly on the go without carrying a hardware scanner
  • Digitizing fragile paper documents without sending scans through third-party cloud servers

How Paperly does it

  1. 01

    Real-time edge detection

    Point your camera at the document. Paperly identifies the page perimeter in real time, locking onto the four corners even against complex desk patterns.

  2. 02

    Perspective correction

    The perspective distortion caused by shooting at an angle is mathematically projected into a true, straightened rectangle with parallel borders.

  3. 03

    Shadow removal & contrast filter

    Adaptive image filters remove hand shadows, smooth page backgrounds to pure document white, and sharpen character outlines for effortless reading and printing.

Questions people ask

A regular camera photo retains perspective skew, surface glare, hand shadows, and large uncompressed image sizes. Paperly detects document borders, straightens the page into a true rectangle, cleans up the lighting, runs text recognition, and bundles pages into an optimized, compact PDF.

Yes. While Paperly's automatic edge detection is highly accurate, you can fine-tune the four corner pins with an interactive magnifying loupe before finalizing the scan.

Yes. The detection algorithm adapts dynamically to US Letter, A4, legal sheets, receipts, business cards, identity cards, and receipts.

Yes. All scans are saved directly into your device's local Paperly library or exported to your local file system. Documents are never transmitted to cloud servers.

Related features

Try document scanner where it runs best.

Paperly for iPhone — private, on-device, and free to download.