Usability

Usability measures effectiveness, efficiency, and satisfaction when specific users pursue specific goals (ISO 9241-11).

QR code usability spans three stages: pre-scan (findable position, clear CTA, adequate size), during scan (sufficient contrast for quick recognition, appropriate error correction), and post-scan (page load speed, mobile optimization, information findability).

Accessibility for elderly and digitally inexperienced users matters - specific instructions like "point your smartphone camera at the QR code" outperform generic "scan the QR code" prompts. Usability testing with real users reveals stumbling points for concrete improvements.