WebDEA is a web-based application using Data Envelopment Analysis (DEA) models for the evaluation of the decision making units (DMUs). It is built for educational purposes as well as to support decision-making in general. The WebDEA includes DEA models under constant and variable returns to scale assumptions as well as their oriented and unoriented variants. Also, weight restrictions can be incorporated to the aforementioned models and post-DEA analysis can be carried out based on cross efficiency analysis (Aggressive and Benevolent versions). The engine for solving the DEA models in WebDEA is the lpsolve solver.