This paper identifies different types of climate change mitigation strategies countries adopted over the last two decades and assesses the policy synergies they might generate. The analysis exploits the rich policy repository of the OECD’s Climate Actions and Policies Measurement Framework (CAPMF). This is the most comprehensive and harmonised mitigation policy database to date, covering more than 120 policy instruments and 50 countries over 2000-20. Statistical cluster analysis yields four types of mitigation strategies, which differ in the variety and stringency of mitigation policies. Until the mid-2000s mitigation strategies were similar and based on few policies and low overall stringency. They started to differentiate in the mid-2000s and then in the mid-2010s as some countries enlarged the variety of policy instruments and raised stringency. Regression results indicate that emissions are negatively associated with the overall stringency of the country’s mitigation strategies. Moreover, this relationship is stronger for mitigation strategies comprising a larger set of instruments, pointing to larger policy synergies.