To determine the feasibility of a randomised controlled trial (RCT) assessing the effects of an experience-based website as a resource for the self-management of chronic asthma.Feasibility, single-blind RCT in 2 regions of England. Randomisation used computer-generated random number sequence in a 1:1 ratio, after baseline data collection, to website access for 2 weeks.Adults (age ≥18 years), with clinically diagnosed asthma as coded in their primary care electronic record, prescribed inhaled corticosteroids for at least 3 months in the previous year, were recruited from 9 general practices.The EXPERT asthma intervention is an interactive PC/laptop/tablet/smartphone compatible website designed with extensive input from adults with asthma. It provides experience-based information and aims to support subjective perception of self-efficacy, self-management and improve health status.Primary outcomes were consent/recruitment, website usage and completion of outcome measures. Secondary outcomes included Partners in Health (PIH) questionnaire, the Chronic Disease Self-Efficacy Scale, the SF36 and the E-Health Impact Questionnaire. Participant blinding postrandomisation was not possible. The analysis was blind to allocation.Recruitment target exceeded. 148 participants randomised (73 intervention group). Age range 19-84 years; 59% female. 121 of 148 (84 62 intervention group) followed up. The median number of logins was 2 (IQR 2-3, range 1-48). Minimal differences of change from baseline between groups; both showed improvement in health state or management of their condition with no significant differences between arms. No adverse events.Recruitment and retention confirmed feasibility. The trends towards improved outcomes suggest that further research on digital interventions based on exposure to others' personal experiences may be of value in the self-management of chronic asthma.ISRCTN29549695; Results.