The E3SM Diagnostics Package for Earth System Model Evaluation can be used alone or embedded into the E3SM workflow to enable seamless transition between model runs and diagnostics. The package includes a group of the most up-to-date analysis datasets to facilitate model validation. It is designed to be adjustable and modular, enabling users to manipulate different aspects of the diagnostics workflow. Numerous configuration options exist to customize data processing and metric computation as well as data visualization.