Nature Materials, Published online: 01 July 2026; doi:10.1038/s41563-026-02650-2Leakage current affects the operation and reliability of electronic devices, but obtaining accurate measurements of leakage current across two-dimensional (2D) materials has been difficult. This article accurately quantifies the leakage current across hBN, MoS2 and WS2 with different thicknesses and compares them with SiO2, which helps predict the performance and reliability of 2D materials-based electronic devices.