This paper provides an overview of options to assess mitigation commitments before Paris and beyond. This includes a review of current activities to assess individual INDCs as well as a discussion of some of the attributes and requirements such assessment needs to fulfil. The paper goes on to explore options of how the assessment could be carried out and linked to the UNFCCC process, followed by a discussion of methodological approaches to assess the ambition of mitigation contributions. In conclusion, it provides some recommendations on a feasible and realistic way forward drawing out potential opportunities and challenges in the process.