<p>Base editing is a precision genome-editing methodology that enables the programmable installation of point mutations with high efficiency. Two major classes of base editors have been developed: cytosine base editors introducing C·G-to-T·A edits, and adenine base editors introducing A·T-to-G·C edits. Since their introduction, base editor use has expanded substantially, and base editors have been applied in many biological and biomedical applications. In this Primer, we provide an overview of the use of base editors in mammalian cells for high-throughput base-editing screens, disease modelling and therapeutic applications. We cover important considerations in experimental design of base-editing experiments, data analysis and interpretation, and best practices for reporting results. We also discuss potential challenges related to reproducibility and limitations, and outline options for optimization and troubleshooting. Our goal is to aid both new and experienced researchers in effectively implementing base editing in their own work.</p>