AtCoder vs Edabit

AtCoder is a free web service for competitive programming contests and practice. Users solve programming problems in Algorithm Contest and Heuristic Contest formats, and can run source code in a browser rather than setting up a local programming environment. Its practice library contains about 5,000 past problems with explanations, and it supports nearly all major programming languages, including C++, Python, Rust, Java, and C#. Beginner Contests take place weekly, Regular Contests about monthly, Grand Contests five to six times a year, and heuristic contests about monthly. Real-time participation in Algorithm or Heuristic contests changes a user's AtCoder rating. AtCoder Jobs lets users apply to companies using their rating for roles including internships and experienced positions. PAST is an online algorithm skills test available in Japanese and English, with problems updated every six months. AtCoder says it has about 200,000 registered users and about 10,000 participants in real-time contests weekly. Its terms limit members to one account and prohibit account sharing, lending, or transfer.

Edabit is a web-based service for practicing programming through interactive coding challenges. Its library is described as containing more than 10,000 problems, with C#, C++, Java, JavaScript, PHP, Python, Ruby, and Swift among the supported languages. Learners submit code and see test results; hints use that context to guide them without simply supplying answers. The site tracks solved challenges and levels, and awards XP according to challenge difficulty. All challenges are free to complete, and the listed Free plan costs nothing. Edabit says it is not currently selling new memberships, and does not offer student-specific or school plans. It is designed primarily for desktop use because coding works best with a physical keyboard. The service is available only to people at least 13 years old. Its privacy policy says passwords are stored encrypted, browser-server traffic uses SSL or HTTPS, and personal information is not shared for marketing or advertising. Session recordings can retain page structure and interactions for up to 30 days.