Since 1995, TIMSS has monitored trends in mathematics and science achievement every four years, at the fourth and eighth grades. TIMSS 2023 is the eighth such assessment, providing nearly three decades of trend data. TIMSS 2023 completes the transition to a fully digital administration, concluding a process that began in TIMSS 2019, and features new and interactive item formats.

TIMSS Advanced studies achievement in advanced mathematics and physics for students in their final year of secondary school. TIMSS Advanced was conducted in 1995, 2008, and 2015.