CF Themer – Themes & Custom Contests for Codeforces

Customize Codeforces with sleek dark themes, focus mode, problem timers, and custom mashup contests!

Dark themes, a distraction-free focus mode, per-problem timers and notes, and custom mashup contests for Codeforces. CF Themer makes Codeforces comfortable for long practice sessions, then adds the tools you wish the site had: a timer and notepad on every problem, a mode that shows only the statement, and a contest builder that makes a timed practice set from the exact topics you want to improve. Built for competitive programmers who want fewer distractions and more solving. 🎨 THEMES • Four hand-tuned themes Monokai, Dracula, Pure Black and Lock-In, a high-contrast focus theme with one red accent, square corners and no motion • Full-site coverage Header, menus, problem lists, statements, sample tests, standings, blogs and syntax-highlighted code • Readability guard Automatically repairs light boxes, pale borders and text that is too dark for your theme, including pop-ups that appear later • Solved and attempted rows Highlighted green and red so you can scan a problem list instantly • Quick switching Toolbar popup, floating ◐ button, or Alt+Shift+T to cycle themes • Printing stays normal Themes apply on screen only 🎯 PRACTICE TOOLS • Focus mode (Alt+Shift+F) Hides everything except the problem statement, with a wide reading column. One shortcut or button brings it all back • Timer and notes on every problem A timer that runs while the tab is visible, plus a notepad for ideas, mistakes and tricks. Saved per problem on your device • Spoiler-free practice Hide problem tags, difficulty ratings and solved counts so they don't give away the solution • Adjustable sample size Make code and sample tests easier to read ⚔️ MASHUP CONTESTS Turn any set of topics into a timed practice contest in seconds. • Pick tags (match any or all), a rating range, number of problems and contest length • Problems of rising difficulty are chosen from the Codeforces problemset • Exclude problems you've solved or tried, and avoid repeats from earlier mashups • A countdown follows you across Codeforces pages, with your problem list one click away • Tags and difficulty stay hidden until the contest ends • Your submissions are checked automatically; you get a solved count and ICPC-style penalty • Share any contest with friends using a short code, and replay past contests from your history 🔒 PRIVATE BY DESIGN • No accounts, no analytics, no ads • Settings, timers, notes and mashup data stay in your browser • The mashup builder asks for your agreement before it reads your handle or submissions, and only talks to the public Codeforces API • One click deletes all your saved data Privacy policy: https://rigvedrajput.github.io/cf-themer/privacy.html Free to use. No account required. CF Themer is an unofficial extension and is not affiliated with, endorsed by, or produced by Codeforces.