There are major gaps in the measurement of the adoption and stringency of countries’ climate actions and policies, notably in a manner coherent across countries, time, sectors and instrument types. The climate actions and policies measurement framework (CAPMF) aims to fill this gap. It is a structured and harmonised climate mitigation policy database that informs about countries’ climate action. The CAPMF was developed under the International Programme for Action on Climate (IPAC). It comprises 128 policy variables, grouped into 56 policy instruments and other climate actions, covering the 52 countries participating in IPAC and the period 2000-2020. The CAPMF is the most comprehensive internationally harmonised climate-related policy database currently available. Results indicate that IPAC countries strengthened their climate action between 2000 and 2020 in terms of both policy adoption and policy stringency, although individual countries progressed at different paces. Policy mixes in many countries changed from cross-sectoral to a more sectoral focus and from non-market to market-based approaches. Importantly, results suggest a positive relationship between stronger climate action and greater emissions reductions but further analysis is needed to fully assess policy effectiveness.