Background: Peer support for people with long-term mental health problems is central to recovery-oriented approaches in mental health care. Peer support has traditionally been conducted offline in face-to-face groups, while online groups on the Internet have increased rapidly. Offline and online peer support groups are shown to have differing strengths and weaknesses. However, little is known about how combining the two formats might be experienced by service users, which this paper aims to illuminate. Methods: In this exploratory and descriptive study, a recovery-oriented Internet-based portal called ReConnect was used by service users in two mental health communities in Norway for 6-12 months. The portal included an online peer support group which also facilitated participation in local offline peer support groups. Both group formats were moderated by an employed service user consultant. Qualitative data about service users' experiences were collected through focus groups and individual interviews and inductively analyzed thematically. Results: A total of 14 female service users 22-67 years of age with various diagnoses participated in three focus groups and 10 individual interviews. Two main themes were identified: (1) balancing anonymity and openness, and (2) enabling connectedness. These themes are further illustrated with the subthemes: (i) dilemmas of anonymity and confidentiality, (ii) towards self-disclosure and openness, (iii) new friendships, and (iv) networks in the local community. Three of the subthemes mainly describe benefits, while challenges were more implicit and cut across the subthemes. Identified challenges were related to transitions from anonymity online to revealing one's identity offline, confidentiality, and barriers related to participation in offline peer support groups. Conclusions: This study suggests that online and offline peer support groups complement each other, and that combining them is mainly described as beneficial by service users. Identified benefits appeared to arise from service users' options of one format or the other, or that they could combine formats in ways that suited their individual values and comfort zones. Moderation by a trained service user consultant appeared essential for both formats and can be used systematically to address identified challenges. Combining online and offline peer support groups is a promising concept for facilitating recovery-oriented care and warrants continued research.