CF Performance Mirror by Pritam Mohanta

Features

1. Contest-wise Solve Time- Average and median solve time per problem index (A, B, C, D…) broken down by contest division — spot exactly where you slow down under pressure.
2. WA% Friction Analysis- Identify your weakest areas by topic, problem rating, or individual problems. See WA, TLE, RTE, MLE, and ERR counts per problem. Click any topic or rating bucket to expand the full problem list with direct links.
3. Division-Aware Breakdown- Stats are automatically split into Div1, Div2, Div3, Div4, and Other — so your Div4 A-problem solves don't inflate your Div1 numbers.
4. Div1+Div2 Round Intelligence- For combined-division rounds, your rating at contest time is used to assign you to the correct division — accurate stats, not guesswork.
5. Three Friction Views- Switch between Topics (tag-level WA%), Ratings (difficulty-bucket WA%), and Problems (flat per-problem list sorted by errors or rating).
6. Time-Range Filters- Filter performance over the last month, 3 months, 6 months, year, 2 years, all time — or pick a custom date range to zoom into any period.
7. Total / Rated / Unrated Toggle- Analyze all contests, only rated ones, or only unrated/virtual ones independently.
8. Hide AC'd Problems- Focus only on unsolved problems to build a targeted practice list. Toggle on/off per session.
9. Min WA Threshold- Filter out noise — only show topics or problems where you've made at least N wrong attempts.
10. Persistent Default Settings- Save your preferred division, time range, view mode, sort order, and filters — they persist across sessions so the card always opens exactly how you like it.
11. Compact, Non-Intrusive UI- Appears seamlessly below the profile box. Automatically matches light and dark themes — no jarring white boxes on dark pages.

How it works

Runs entirely client-side as a browser extension content script on any Codeforces profile page (https://codeforces.com/profile/<handle>). Fetches data from three Codeforces public APIs:

user.status — your submission history
contest.list — contest metadata
user.rating — rated contest history and rating timeline

No data is stored on any server. Everything is computed in your browser. See the privacy policy for full details.

What's New

1. Three friction views — Topics, Ratings, and Problems with per-problem error breakdown (WA / TLE / RTE / MLE / ERR).
2. Division-aware stats — Div1 through Div4 split with smart Div1+Div2 round handling using your actual rating at contest time.
3. Problems view — flat sortable list of every problem you've had errors on, with tags, difficulty, and direct links.
4. Custom date range — analyze any specific window of time, not just presets.
5. Persistent settings — your defaults are remembered across sessions.
6. Hide AC'd toggle + Min WA filter — cut the noise, focus on what needs work.
7. Improved dark/light theme detection — dynamically adapts to the page with no flicker.