Most document-scanner apps want your contracts, receipts, and passport scans uploaded to their cloud. DocLensPro just doesn't. Everything — edge detection, perspective correction, OCR, PDF export — happens on your phone. No account, no cloud, no telemetry. It's the document scanner you wish your accountant's scanner was.
What is DocLensPro?
DocLensPro is an open-source (Apache 2.0) document scanner for Android that lets you photograph paper documents and convert them into clean PDFs with searchable text. Edge detection uses OpenCV plus a custom-trained ONNX inference model to find the document boundaries automatically. Perspective correction straightens skewed angles. Tesseract OCR — running entirely offline — extracts text so the resulting PDF is fully searchable. Nothing leaves your device.
F-Droid compliant, built from source (no prebuilt binaries), and 100% offline.
Key Features
- Auto edge detection — Aim your camera at a document and the app finds the corners instantly. Manual adjust is one tap away if it misses
- Perspective correction — Photos taken at angles get straightened to a flat, readable rectangle automatically
- Grayscale enhancement — Optional filter that makes faded receipts and old paper readable
- Offline OCR (Tesseract) — Extract text from scanned documents without internet. Resulting PDF is searchable in any PDF reader
- Searchable PDF export — Save scans as standard PDFs that work everywhere — email, cloud drives, printers
- Material 3 dark mode — Clean, modern UI that respects your system theme
- Privacy by design — Zero network calls during scanning. Verifiable via the open-source code
How It Compares
- vs. Adobe Scan / Microsoft Lens — Both are cloud-first. They sync to Adobe Document Cloud or OneDrive. DocLensPro stays local. If you scan tax documents, ID copies, or medical records, that difference matters
- vs. CamScanner — CamScanner had a notorious malware incident in 2019 and remains a freemium app with aggressive ads. DocLensPro is open-source and free with no ads
- vs. Genius Scan — Genius Scan is great but proprietary. DocLensPro's open-source nature means you can audit it (or pay someone to)
- vs. Doczio — Doczio is a full document suite (viewer, editor, converter, scanner). DocLensPro focuses purely on scanning. If you want both, install both
The Verdict
Pros
- 100% offline — your documents never leave your phone
- Open source (Apache 2.0) — auditable, F-Droid compliant
- OpenCV + ONNX edge detection works on real-world papers (curled receipts, weird angles)
- OCR creates standard searchable PDFs
- No ads, no upsell, no account
Cons
- OCR is English-only out of the box — Hebrew, Arabic, CJK need extra Tesseract data files
- Less polished interface than Adobe Scan
- No automatic cloud backup (intentional, but means you must manage your own)
Who It's For
Anyone who scans sensitive documents on Android — tax papers, contracts, ID copies, medical records. Professionals like lawyers and accountants who can't legally upload client documents to a third-party cloud. Privacy-conscious users who refuse cloud-first scanners on principle.
Not for: people who want auto-sync to Google Drive or built-in collaboration — that requires cloud, which DocLensPro deliberately avoids.
Final Word
DocLensPro is what happens when "privacy-first" stops being a marketing slogan and becomes the actual architecture. It's a competent scanner with serious edge detection and OCR — but its real value is that none of that runs on someone else's server. Score: 8.7/10.