Summary Electrochemical reduction of CO2 (CO2RR) to hydrocarbons and alcohols is a promising yet intricate catalytic process with large associated overpotentials. On Cu, the most active metal, factors such as pH, solvation, anions and cations in solution, in addition to the catalysts’ structure, modify the reaction mechanism and play an important role on the catalytic activity and selectivity. Such an extraordinary complexity calls for an in-depth understanding of CO2RR that eventually leads to its optimization. In this brief review, we illustrate how computational methods have aided in recent years to gain insight on CO2RR. We show the achievements and limitations of well-established methods based on Gibbs energy diagrams, calculations in vacuum, the computational hydrogen electrode and scaling-relation-based volcano plots. Besides, we review advances on kinetics of electrochemical steps, structure-sensitive screening, ion effects, and machine learning.