Toggle competitive programming macros and typedefs inline.
Users
57
+5 in 30 days
Rating
5.0 / 5
unchanged in 30 days
Ratings
4
0 in 30 days
Store rank
#104K
#87K among extensions
Version
0.3.1
updated 13 Aug 2026
Users
monthly, 2 months
Latest, 19 Oct 2026:57 usersMove the mouse over the chart for any month
Ratings count
monthly, 2 months
Latest, 19 Oct 2026:4 ratingsMove the mouse over the chart for any month
The Chrome Web Store rounds user counts down to the leading digit, so the user line moves in steps. The ratings count is exact and is the better signal of real adoption.
About Codeforces Un-definer
Codeforces Un-definer is a small reading helper for competitive programming source code pages.
It adds intuitive toggle buttons next to C++ #define macros, typedef declarations, and simple using aliases. When you click a button, the declaration line is crossed out and matching usages in the displayed code are rewritten inline.
Supported sites:
- Codeforces
- AtCoder
- QOJ
- OJUZ
- CodeChef
Features:
- Toggle #define macros directly on submission pages.
- Toggle simple typedef and using aliases.
- Red/green buttons for #define macros.
- Orange/blue buttons for type aliases.
- Highlights lines that were changed.
- Works locally in the browser.
- Does not collect, store, or transmit user data.
Codeforces Un-definer is designed to make macro-heavy competitive programming submissions easier to read. It is a reading helper, not a full C++ preprocessor, so very complex macros, template tricks, and unusual formatting may not be expanded correctly.
Project page:
https://github.com/hggfhggf/Un-definer/
Codeforces blog post:
https://codeforces.com/blog/entry/155863
Codeforces Un-definer is an independent tool and is not affiliated with, endorsed by, or sponsored by Codeforces or any other supported platform.