 A two-armed randomized clinical superiority trial will be performed to compare OA treatment by a web-based program, Joint Academy, with traditional face-to-face OA-school in 1600 adults with clinically verified OA. Using intention-to-treat analysis, evaluations will be performed at baseline, after 6 weeks and after 3, 6 and 12 months. The primary outcome is pain. Secondary outcomes are physical functioning, health-related quality of life, self-reported function, amount of time of physical activityexercise, overall satisfaction and a health-economic analysis. The primary endpoint will be at 6 months. Data will be monitored using web-based questionnaires in Joint Academy, and regular paper questionnaires for the face-to-face treatment. 