Collaborative project-based learning is one pedagogical approach which has the potential to play a meaningful role in synchronous online teaching but its use at second level, or high school, is under-explored. This paper describes the use, in an online setting, of the Bridge21 pedagogical model for collaborative project-based learning with secondary school students. It compares the experiences of a group (N = 119) of students (aged 15–16) who, in an Emergency Remote Teaching offered during Covid, experienced the model in an online, synchronous modality with that of a group (N = 253) who participated face-to-face in the following year.Two related research questions are addressed. (RQ1) Are the Bridge to College collaborative project-based learning workshops as effective, in terms of enhancing secondary school student confidence in Transversal Skills, when delivered in a synchronous online modality as they were when delivered face-to-face? (RQ2) If so, then what are the elements of the workshops which contribute to their effectiveness?Data on improvement in student confidence in Transversal Skills show that the online experience was on a par with face-to-face offerings. Student feedback suggests that the focus on collaborative work, and the structured approach to PBL, were key factors in the success of the model in the online setting. The modifications needed to adapt the model for use online were minimal. Thus, the contribution of the paper is to provide a model for synchronous online learning, for secondary schools, which preserves the benefits arising from face-to-face collaborative PBL.