Background: Electronic portfolios (e-portfolios) are valuable tools to scaffold workplace learning. Feedback is an essential element of the learning process, but it often lacks quality when incorporated in ePortfolios, while research on how to incorporate feedback into an ePortfolio design is scarce. Objectives: To compare the ease of use, usefulness and attitude among three feedback formats integrated in an ePortfolio: open-text feedback, structured-text feedback and speech-to-text feedback. Methods: In a mixed method designed experiment, we tested with 85 participants from different healthcare disciplines, three feedback formats in an ePortfolio prototype. Participants provided feedback on students' behaviour after observing video-recorded simulation scenarios. After this, participants completed a questionnaire derived from the Technology Acceptance Model (TAM). The experiment ended with a semi-structured interview. Results: Structured-text feedback received highest scores on perceived ease of use, usefulness, and attitude. This type of feedback was preferred above open-text feedback (currently the standard), and speech-to-text feedback. However, qualitative research results indicated that speech-to-text feedback is potentially valuable for feedback input on-premise. Respondents would use it to record short feedback immediately after an incident as a reminder for more expanded written feedback later or to record oral feedback to a student. Implications: Structured-text feedback was recommended over open-text feedback. The quality of the speech-to-text technology used in this experiment, was insufficient to use in a professional ePortfolio but holds the potential to improve the feedback process and should be considered when designing new versions of ePortfolios for healthcare education.