Compare software

LeetCodeExercism
Freemium

Many problems are free; a paid Premium subscription is offered.

 Free

Free to use.

Web Web
  • Large set of algorithm and data structure problems
  • Solutions are written and run in the browser
  • Exercises in dozens of programming languages
  • Optional feedback from mentors
  • Focused on puzzle-style problems rather than building real projects
  • Requires an internet connection
  • Mentor availability can vary by language
  • Focused on practice exercises rather than full courses
Web application Web application
Closed source Closed source
License not stated License not stated
Not stated if an account is needed Not stated if an account is needed
Needs internet Not stated if it works offline

Checked October 1, 2026

Checked September 23, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.