Hello Codeforces community,

Many of us spend hours here: solving problems, reading editorials, and participating in contests. While Codeforces is already amazing, there is one feature that would make it more comfortable and modern: a dark/light mode toggle.

Why Dark Mode?

• Reduces eye strain during long practice sessions, especially at night.
• Matches modern web standards since most competitive programming and developer platforms already have it.
• Makes the site more accessible and user-friendly.

Suggested Feature

• A simple toggle button in the header or settings.
• Persistent choice: the site remembers the last mode you used.
• Covers all main areas:

• Problem statements

• Editorials
• Submissions and contest standings
• Code editor and tables
• Blogs and comments

Why Official Dark Mode is Better than Extensions

Some people might say: "Just use Stylus, Tampermonkey, or a browser extension." But an official dark mode would be much better for several reasons:

1. Seamless experience: no need to install or configure anything. It works for everyone by default.
2. Consistency and reliability: extensions often break when Codeforces updates its HTML or CSS. An official mode would always be maintained.
3. Full integration: extensions usually only restyle backgrounds and text. An official mode could properly theme everything including the editor, tables, and rating graphs.
4. Accessibility: official mode can support system preferences (prefers-color-scheme), so it can switch automatically with the operating system.
5. Performance and security: extensions inject extra scripts which can slow down the site or pose risks. A native feature is faster and safer.
6. Community adoption: if Codeforces itself provides it, far more people will use it.

Closing Thoughts

Dark mode is not only a visual change but also about comfort and usability for the community.

I hope that MikeMirzayanov and the Codeforces team will consider this feature in the future.

What do you think? Would you like to see a dark/light mode toggle added to Codeforces? If enough people support this, perhaps the Codeforces team could bring it in a future update.