atcoder.jpSites like atcoder.jp

We compare each site’s description, category and technology with the other sites we’ve analysed and list the closest matches. Only sites that pass our safety checks appear.

Not necessarily. They are sites that look alike in what they describe and how they are built — useful as alternatives, but not a claim that the companies compete.

A sponsored listing is a paid placement. It is always labelled and never replaces a real match.