When comparing Hackr.io vs exercism.org, the Slant community recommends exercism.org for most people. In the question“What are the best resources to learn JavaScript?” exercism.org is ranked 3rd while Hackr.io is ranked 11th. The most important reason people chose exercism.org is:
Rather than merely test for code correctness, Exercism uses peer review to improve general programming techniques. Users are encouraged to comment on others' solutions, and refine their own based on feedback.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Community trust
Instead of getting a recommendation from a single dev, you get recommendation from the entire programming community.
Pro Recommendation for every programming language/framework/library
You can find Python as well as Jenkins.
Pro Nice filters
Free, Video, Book, Beginner, Advanced, etc.
Pro Human review and feedback
Rather than merely test for code correctness, Exercism uses peer review to improve general programming techniques. Users are encouraged to comment on others' solutions, and refine their own based on feedback.
Pro Practice with production tools
Unlike many code practice websites, Exercism requires the user to develop and test entirely offline, submitting only the finished code. This promotes familiarity with essential tools and workflow, not just the bare language.
Cons
Con Custom commandline client
Exercism requires using a CLI utility to fetch and submit exercises. This is inconvenient compared to web-only alternatives, and poses an additional barrier to entry for some users.