PHABLABS 4.0 aims to integrate photonics in a durable way into the rapidly expanding ecosystem of European Fab Labs and Makerslabs, resulting in a larger and better skilled photonics workforce with superior innovation capacity to achieve a lasting, positive impact on the next revolution in digitization. Combining the forces of top experts from 13 European photonics institutes and STEM-oriented organizations with the Fab Lab stakeholders, PHABLABS 4.0 will devise and deliver a comprehensive suite of 33 Photonics Workshops, 11 Photonics Challenger projects and Photonics Toolkits to enhance Fab Labs and Makerslab with photonics activities aimed at 3 specific target groups: young minds (age 10-14), students (age 15-18) and young professionals and technicians (age 18+). These activities will be extensively tested in 14 existing Fab Labs with the purpose of rolling them out to the entire growing network of European Fab Labs as a proven model at the end of the project. They will stimulate hands-on design, fabrication, experiments, and the building of innovative systems with photonics, and in this way nurture the 21st Century skills of the participants. In that sense the PHABLABS 4.0 project will harness the power of the growing innovation ecosystem of the Fab Labs and equip it with sufficient material to really engage, excite and educate youngsters, students, technicians and young professionals alike in the skills of working and innovating with light. The ultimate impact of PHABLABS 4.0 will be seen in the emergence of a much larger and better trained workforce with 21st Century skills capable of translating the potential of photonics as a key enabling technology into tangible products for the benefit of society.