BACKGROUND: Chronic pain affects 20% of Europe's population, reducing work capacity and quality of life. Despite its impact, few digital tools support pain management or employer-employee collaboration. Sustainable WorkEr, a digital support for Persons with chronic Pain and their Employers (SWEPPE), a digital intervention, helps employers sustain the employment of individuals with musculoskeletal pain through workplace support. AIM: This mixed methods evaluation aims to assess the experiences of employees dealing with musculoskeletal pain, as well as their employers, in using SWEPPE on-site at the workplace for seven months, and to explore how they specifically utilised the app. METHODS: Ten employers and 15 employees at a Swedish industrial company were recruited for this study. Employees used the SWEPPE app alongside regular rehabilitation, while employers accessed it via a web platform. Data were gathered through an HR-developed questionnaire, interviews by two researchers, and user data from the SWEPPE database. RESULTS: SWEPPE improved communication and collaboration between employees and employers through structured updates and information-sharing. Employers appreciated the insights, enhancing their understanding of employees' challenges and making meetings more productive. Access to employees' goals and strategies streamlined processes, increasing awareness of how pain affected work ability and fostering a more supportive work environment. CONCLUSIONS: The SWEPPE app helped employees track their health, work ability, and goals, increasing their awareness of how symptoms affected their work. It fostered structured employee-employer dialogue, enabling collaborative plans that supported both employee recovery and employer readiness for the RTW process. This proactive approach encouraged sustainable workplace adjustments, promoting work sustainability.