Inclusion Criteria:  Low self-esteem, as indicated by rating of < 20 the Rosenberg Self-Esteem Scale.  Age between 18 and 25 years old. Access to a computer, smartphone, or tablet with internet access. Write and speak Swedish. In case of use of psychotropical medication, a stable dose for the past three months prior to registration and no planned changes during the treatment.  Exclusion Criteria:  Other ongoing psychological treatment that affects the treatment received in the study.  No comorbid severe depressive symptoms and no suicidal plans. Ongoing alcohol use disorder, as indicated by Alcohol Use Disorders Identification Test (AUDIT).  Severe psychiatric comorbidities (e.g. psychosis, anorexia nervosa) that requires specialist care within the regular psychiatric care.