Hello Codeforces!

While working through the problemset, I found the native filters on Codeforces a bit poor. I wanted more sorting options and finer control over problem difficulty. This frustrated me enough, so I started searching for extensions to fix it. Either I’m blind or they don't exist — I couldn't find one that fixes this problem.

That's how CF Helper came about. It's a Firefox extension that adds more tools for finding practice problems directly in the Codeforces problemset.

Features:

• Filter problems by difficulty, solved count, name, and problem or contest ID.
• Include or exclude tags, matching either all selected tags or any of them.
• Sort problems, save filter presets, and bookmark problems.
• Pick a random problem matching your current filters.
• Hide tags and difficulty to avoid hints before solving.
• Load public submission history for a Codeforces handle and filter by accepted submissions or previous attempts.
• Export filtered problems and bookmarks as a text file.

The interface is available in English and Russian. To use submission-based filters, enter your Codeforces handle in the extension's settings and load your history. These filters only consider loaded submissions, so older accepted submissions may be missing if your history is incomplete.

Install from Mozilla Add-ons

Feedback, bug reports, and suggestions are welcome!