A curated list of popular programming challenge websites to improve your coding skills.
| Website | Link | Description |
|---|---|---|
| LeetCode | leetcode.com | Popular platform with coding interview questions, supports multiple languages, includes discussion forums and company-specific questions |
| HackerRank | hackerrank.com | Comprehensive platform with coding challenges in algorithms, data structures, AI, databases, and more. Used by companies for technical assessments |
| CodeWars | codewars.com | Gamified coding challenges (kata) ranked by difficulty, with a strong community focus and peer review system |
| Exercism | exercism.org | Free platform with mentor-based learning, offers exercises in 60+ languages with personal feedback |
| Project Euler | projecteuler.net | Mathematical and computational programming problems that require more than just coding skills |
| Coderbyte | coderbyte.com | Interview prep platform with coding challenges, tutorials, and career resources |
| TopCoder | topcoder.com | Competitive programming platform with regular contests, including algorithm, design, and development challenges |
| Codeforces | codeforces.com | Competitive programming platform with regular contests and extensive problem archive |
| AtCoder | atcoder.jp | Japanese competitive programming platform with beginner-friendly contests and educational content |
| Advent of Code | adventofcode.com | Annual December event with daily programming puzzles, great for any skill level |
| CodeChef | codechef.com | Competitive programming platform with monthly contests and practice problems |
| SPOJ | spoj.com | Sphere Online Judge - vast collection of programming problems with online judge |
| Kaggle | kaggle.com | Data science and machine learning competitions with real-world datasets |
| CodinGame | codingame.com | Learn programming through games and challenges, supports 25+ languages |
| HackerEarth | hackerearth.com | Coding challenges, hackathons, and recruitment solutions |
| Edabit | edabit.com | Beginner-friendly platform with bite-sized coding challenges |
| Codility | codility.com | Platform focused on technical recruitment with programming lessons and challenges |
| LintCode | lintcode.com | Coding interview platform similar to LeetCode with additional system design problems |
| GeeksforGeeks | geeksforgeeks.org | Comprehensive computer science portal with tutorials, coding problems, and interview preparation |
| Beecrowd (URI) | beecrowd.com.br | Online judge with over 1000 problems for beginners to advanced programmers |
| Kattis | open.kattis.com | Programming problem archive with problems from programming competitions, supports 20+ languages |
| UVa Online Judge | onlinejudge.org | One of the oldest online judges with thousands of competitive programming problems |
| CodeSignal | codesignal.com | Technical interview practice and assessment platform with arcade-style coding challenges |
| Timus Online Judge | timus-online.ru | Archive of programming problems from Russian competitive programming contests |