Abstract Learners’ independence and self-regulated learning (SRL) may be achieved by online teaching, promoting learners’ 21st century skills. Transitioning into online learning and teaching requires a variety of teachers’ knowledge types and competencies. Mapping these knowledge types with a dedicated tool can help improve teachers’ professional development processes to enhance the SRL of teachers and subsequently students. We aimed at investigating the types of knowledge chemistry teachers expressed in online assignments they had designed, which included guidelines to foster their students’ SRL, and reviewing their reflections upon implementing these assignments. The participants were 20 high school chemistry teachers, who took part in two professional development programs focusing on fostering students’ SRL skills in online assignments, the teachers had designed. Research tools included teachers’ online assignments and teachers’ written reflections. We analyzed the assignments using a special rubric, which consists of three types of teachers’ knowledge: technological pedagogical and content knowledge (TPACK), assessment knowledge (AK), and SRL. Findings show that the analysis rubric of online assignments, designed by teachers, enabled identifying various teacher knowledge types and their levels. The use of a validated rubric for mapping and assessing teachers’ knowledge types is a methodical contribution to research on chemistry teachers’ professional development.