CF Performance Mirror is a free Chrome add-on designed for Codeforces users. It provides insightful analytics on a user’s performance in contests by displaying contest-wise average and median solve times per problem index. Additionally, it highlights high wrong-attempt percentages, allowing users to identify frictional topics that may need further study. The tool features toggle modes for Total, Rated, and Unrated contests, ensuring flexibility in performance analysis.

The add-on operates as a client-side content script on Codeforces profile pages, utilizing public APIs to gather relevant data without uploading personal information. Upon installation, users can easily access the compact card that appears beneath their profile box, offering a streamlined and non-intrusive interface for performance evaluation. This tool is ideal for those looking to improve their competitive programming skills by understanding their contest performance better.