Hello, Codeforces!

Some of you may already know about the CF Cheater Highlighter extension — an open-source browser extension created by macaquedev and AksLolCoding that highlights known cheaters directly on Codeforces pages. The project has been around on GitHub for a while, but installing it required manually loading an unpacked extension.

I've now hosted it on both the Chrome Web Store and Firefox Add-ons, so you can install it in one click.

What does the extension do?

Once installed, the extension automatically highlights flagged handles with a red background anywhere on Codeforces — standings, profiles, blogs, problem pages, you name it. Flagged users also get a "CHEATER" label appended to their handle so they're impossible to miss.

The cheater data comes from the CF Cheater Database, a community-driven platform where users can report suspected cheaters with evidence. All reports are admin-reviewed before anyone gets flagged. You can also search the database or appeal a mark if you think it was made in error.

The extension fetches the latest list in the background and caches it locally, so it's fast and requires zero configuration. Just install and go.

Install

• Google Chrome: Chrome Web Store
• Mozilla Firefox: Firefox Add-ons
• Source Code: GitHub

Credits & Thanks

All credit for building this project goes to macaquedev and AksLolCoding — they designed and developed both the extension and the cheater database. I just handled getting it published on the Chrome and Firefox extension stores so it's easier for everyone to install.

If you run into issues or have suggestions, feel free to open an issue on GitHub or drop a comment below.