BACKGROUND: Electronic personal health records (ePHRs) play a key role in the digitalization of healthcare, but older adults, often less familiar with digital tools, face access challenges. This study assesses the effects of an interactive, microlearning-based e-learning platform on improving older adults' ePHR competencies. METHODS: To examine the effects of e-learning platform use on competencies, a pilot trial was conducted with two study groups. One group consisted of young-old adults (YOA) aged 50 to 64 years, and the other of older adults (OA) aged 65 years and older. Participants were recruited via senior organizations and facilities, newsletters and an internal database. Both groups used the learning platform for one week. Participants' ePHR knowledge (12-item questionnaire) and usage skills (completion time for three ePHR tasks) were measured pre- and post-intervention on site. The intention to use (ITU) the ePHR was surveyed using a Technology Usage Inventory subscale. The usability of the platform was assessed using the System Usability Scale. RESULTS: Twenty-eight participants (mean age YOA = 56.86, OA = 75.15 years) completed the study, with more women in both groups (YOA: 78.57%, OA: 57.14%). Knowledge improved significantly in both groups: OA increased their median correct answers from 7.00 to 9.00 (p = .019, r = .63), YOA increased from 7.00 to 10.00 (p = .001, r = .86). Median task completion times also decreased for both groups: OA from 746.50 to 539.00 s (p = .002, r = .82), YOA from 487.00 to 351.00 s (p = .012, r = .67). There were no significant differences between groups in terms of knowledge (p = .125) or skill acquisition (p = .144). Across the entire population, median ITU scores decreased from 282.00 to 262.00 (p = .038, r = .39), indicating a reduced intention to use the ePHR, though no changes were observed within groups. The platform's usability scored a mean of 64.04, suggesting high marginal usability. CONCLUSION: Both OA and YOA improved their ePHR competencies after using the learning platform, with no significant differences between groups. The findings suggest that e-learning can enhance ePHR competence in older adults, though improvements in platform usability are needed for wider application in future studies. TRIAL REGISTRATION: German Clinical Trials Register (registration number: DRKS00031730), registered on 20/04/2023-prospectively registered.