Objectives: Research on digital platform work increasingly highlights unclear employment arrangements and pressures related to algorithmic management. This study aimed to describe psychosocial working conditions in web-based and on-location gig work using the job demands‑resources (JD-R) model and examine associations between job demands, job resources, factors preventing resource depletion (FPRD), and health outcomes among platform workers. Material and Methods: Cross-sectional data were drawn from the GIG-OSH project conducted in 7 European countries (Belgium, Denmark, Finland, Poland, Spain, Sweden, and the United Kingdom). Data were collected through an online survey in November 2023 – April 2024. The analytic sample comprised 3299 platform workers (1476 on-location, 1823 web-based). A project-specific questionnaire assessed socio-demographic characteristics, employment conditions, workload, occupational safety and health hazards, psychosocial working conditions, algorithmic management, and health outcomes. Psychosocial factors were classified as job demands, job resources, or FPRD within an extended JD-R framework. Results: Platform work was characterized by an imbalance between job demands and resources, particularly among onlocation workers. Compared with web-based workers, they reported greater exposure to emotionally disturbing situations, aggression, violence, discrimination, and sexual harassment. Working alone was common in both groups but more prevalent in web-based work. Factors preventing resource depletion indicators, especially absence of fines and protection against fraudulent bookings, were more favourable in web-based work. Higher job demands were significantly associated with poorer health outcomes, with emotionally disturbing situations showing the strongest effect. Job resources demonstrated modest protective associations, whereas FPRD indicators, particularly not working while ill, were consistently associated with better health. Conclusions: Platform work involves substantial psychosocial risks linked to poorer well-being and health, supporting the JD-R model. Distinct psychosocial profiles of web-based and on-location work highlight the need for targeted occupational health and platform policy interventions. Int J Occup Med Environ Health. 2026;39(5)