About QR Code Check
QR Code Check is a free QR code scanner that analyses links for security threats before you open them. Scan from your camera, paste screenshots, or import images -- then get an instant safety assessment powered by multiple threat intelligence sources and on-device AI.
The app uses Google Web Risk, URLhaus, heuristic analysis, and on-device machine learning to detect phishing, malware, social engineering, and 14 other threat types.
Frequently Asked Questions
How does QR Code Check scan QR codes?
Point your camera at any QR code for real-time detection. You can also import photos from your library or paste screenshots from emails, messages, and documents. The app uses Apple's Vision framework to detect QR codes on-device.
What do the risk tiers mean?
Safe (green) means no threats were detected. Caution (yellow) means minor concerns were found. Warning (orange) means significant risk indicators were detected. Danger (red) means the URL was flagged by one or more threat intelligence providers as malicious.
Is my data sent to external servers?
Only the decoded URL text is sent to Google Web Risk and URLhaus for threat lookups. No images, device identifiers, location data, or personal information is ever transmitted. All AI analysis runs entirely on your device.
How do the on-device AI models work?
QR Code Check includes four machine learning models (Random Forest, XGBoost, Decision Tree, SVM) that analyse URL features locally using Apple's CoreML framework. They examine 31 features of each URL including structure, character patterns, domain characteristics, and entropy to detect threats. All processing happens on your device -- no data is sent to AI servers.
How do I delete my scan history?
Open the app, go to Settings, and tap "Clear All History" under Data Management. This permanently deletes all scan records from your device. You can also clear trusted URLs separately.
What is a "trusted URL"?
When you open a flagged link, you can choose "Open & Remember This Link" to add it to your trusted list. Trusted URLs skip risk warnings on future scans. You can clear all trusted URLs in Settings > Security.
Can the app guarantee a link is safe?
No. A "Safe" rating means no threats were detected by the sources checked at that time. New malicious sites can appear before threat databases update. Always exercise your own judgement when visiting any link.
What risk sensitivity level should I use?
Strict -- best for cautious users who want maximum warnings. Standard (recommended) -- balanced protection for everyday use. Relaxed -- for experienced users who only want alerts on high-confidence threats.