Hands-on coding exercises, challenges, and real-world practice platforms.

Subcategories

• Coding Exercises & Practice - 55 resources (25 free, 20 freemium, 10 paid)
• Algorithms & Data Structures - 41 resources (33 free, 8 freemium, 0 paid)
• SQL & Database Practice - 34 resources (26 free, 7 freemium, 1 paid)
• Programming Quizzes & MCQs - 37 resources (32 free, 5 freemium, 0 paid)

All Resources (167)

Coding Exercises & Practice

• Aizu Online Judge Free
  • Contest platform and problem archive from the University of Aizu featuring programming contest problems.
• AtCoder Free
  • Japanese competitive programming contests and practice problems.
• CodeChef Free
  • Competitive programming platform with monthly contests and practice problems.
• Codeforces Free
  • Competitive programming contests with real-time rating system.
• CodeKata Free
  • Dave Thomas's collection of coding katas designed to build skill through deliberate practice and repetition.
• Codewars Free
  • Community-driven coding challenges (katas) in multiple programming languages.
• CodinGame Free
  • Gamified coding challenges and programming puzzles with multiplayer.
• CodingBat Free
  • Free practice problems for Java and Python with instant testing.
• CS Academy Free
  • Online judge hosting biweekly contests with live chat, interactive lessons, and an integrated online editor.
• DevChallenges Free
  • Project-based coding challenges for front-end, full-stack, and responsive web development with design specs.
• Exercism Free
  • Free code mentorship and practice in 70+ programming languages with mentor feedback.
• Exercism - Mentoring Free
  • Free one-on-one mentorship for code improvement in 70+ languages.
• Gophercises Free
  • Free Go programming course with hands-on mini-projects teaching the language through building small apps.
• Interviewing.io Free
  • Free anonymous technical interview practice with real engineers.
• JSChallenger Free
  • Focused JavaScript exercises covering arrays, dates, objects, and DOM manipulation with instant feedback.
• Kickstart Free
  • Free coding interview practice with Google engineers.
• OmegaUp Free
  • Community-based competitive programming training platform that hosts the Mexican Olympiad in Informatics.
• Pramp Free
  • Free peer-to-peer mock interviews for technical and behavioral questions.
• Rosetta Code Free
  • Programming chrestomathy site with hundreds of tasks solved in many languages for comparative practice.
• Sanfoundry Free
  • Thousands of MCQs, programming questions, and technical interview resources.
• Sphere Online Judge Free
  • Large collection of algorithmic problems with community solutions.
• The Python Challenge Free
  • Series of puzzles requiring Python code to advance to the next level blending math and programming.
• Timus Online Judge Free
  • Russia's largest archive of programming problems with automatic judging from Ural Federal University contests.
• TopCoder Free
  • Competitive programming arena and software development challenges.
• Virtual Judge Free
  • Platform that lets users create virtual contests by aggregating problems from many notable online judges.
• AlgoDaily Freemium
  • Daily coding interview challenges with detailed explanations designed to help land software engineering jobs.
• CheckiO Freemium
  • Coding game platform where players solve Python and TypeScript missions to progress through island levels.
• Codeasy Freemium
  • Story-driven C# coding course where you solve exercises to advance a military-themed narrative.
• Codebasil Freemium
  • Mock coding interviews with real-time collaboration.
• Codecademy Freemium
  • Interactive coding platform with exercises and projects across many languages and technologies.
• CodeCrafters Freemium
  • Recreate popular tools like Redis, Git, and HTTP servers from scratch by completing step-by-step coding tasks.
• CodeHS Freemium
  • Interactive coding exercises for students and teachers with autograding spanning K-12 to AP level.
• Codelab Freemium
  • Interview preparation platform with coding problems and company tests.
• Codemia Freemium
  • Real-world software engineering exercises and system design practice.
• CodeStudio by Coding Ninjas Freemium
  • Indian platform with coding problems, guided interview tracks, and mock tests curated by mentors.
• Codility Freemium
  • Programming tasks and online interviews for developers.
• Daily Coding Problem Freemium
  • Daily coding interview problems sent to your inbox.
• Edabit Freemium
  • Beginner-friendly coding challenges with instant feedback in multiple languages.
• GreatFrontEnd Freemium
  • Frontend-focused coding exercises, UI challenges, and interview prep.
• HackerEarth Freemium
  • Coding challenges, hackathons, and interview preparation platform.
• HackerRank Freemium
  • Coding challenges, algorithms, data structures, and interview preparation.
• LeetCode Freemium
  • Technical interview preparation with 3000+ coding problems and mock interviews.
• Python Principles Freemium
  • Python-focused exercises with instant verification organized by topic to build core programming skills.
• Sololearn Freemium
  • Mobile-friendly coding exercises and bite-sized challenges across many languages with community competitions.
• TestDome Freemium
  • Pre-employment testing platform with programming exercises.
• Interview Pro Paid
  • Mock interviews with engineers from FAANG companies.
• AlgoExpert Paid
  • Interview prep platform with curated algorithm problems and video solutions.
• AlgoExpert - Systems Expert Paid
  • System design interview course with real-world architecture problems.
• CodeInterview Paid
  • Mock interviews with real engineers from top companies.
• CoderPad Paid
  • Live coding interviews and technical assessments.
• Devskiller Paid
  • Technical assessment platform with real-world coding tests.
• HireVue Paid
  • Code-based assessments and technical interviews platform.
• Interview Cake Paid
  • Interview preparation with guided practice problems and solutions.
• Interview Camp Paid
  • System design and coding interview preparation course.
• VetBoss Paid
  • System design and coding interview simulation with real-world scenarios.

Algorithms & Data Structures

• A2OJ Free
  • Problem sets organized by difficulty and topic.
• Algo Deck Free
  • Open-source collection of 200+ algorithmic flashcards for quick review and interview prep.
• Algomation Free
  • Algorithm visualization library using JavaScript generators to animate execution of common algorithms.
• Algorithms Illuminated Free
  • Tim Roughgarden's companion site with lecture videos and slides for his algorithms book series.
• AtCoder Problems Free
  • AtCoder practice problems with difficulty ratings.
• basecs Free
  • Medium blog by Vaidehi Joshi with illustrated in-depth tutorials on algorithms and data structures.
• Code Abbey Free
  • Programming problems for beginners to experts.
• Codeforces - Problems Free
  • Database of competitive programming problems.
• Codeground Free
  • Practice platform with algorithmic problems.
• Competitive Programmer's Handbook Free
  • Antti Laaksonen's free book introducing competitive programming for IOI and ICPC aspirants.
• CP-Algorithms Free
  • Comprehensive archive of algorithms and data structures with implementations.
• CSES Problem Set Free
  • Competitive Programming Essential Skills problem set.
• E-Maxx Algorithms Free
  • Widely-referenced Russian tutorial site covering a huge range of competitive programming algorithms.
• GeeksforGeeks Free
  • Computer science tutorials, algorithm explanations, and practice problems.
• HackerEarth Code Monk Free
  • Step-by-step tutorials on essential competitive programming topics with practice problems.
• IDeserve YouTube Free
  • YouTube channel with detailed algorithm and data structure interview tutorials and walkthroughs.
• Kattis Free
  • Programming contest problems from various competitions.
• KTH KACTL Notebook Free
  • Well-organized competitive programming team notebook from KTH Royal Institute.
• MIT 6.006 Introduction to Algorithms Free
  • MIT OCW video lectures and materials for the classic undergraduate algorithms course.
• mycodeschool YouTube Free
  • High-quality video tutorials on basic programming data structures and algorithms.
• NeetCode Free
  • Curated coding problems for interview preparation.
• OI Wiki Free
  • Community-driven Chinese wiki covering competitive programming algorithms and data structures.
• Project Euler Free
  • Mathematical and computational programming problems.
• See Algorithms Free
  • Interactive site that visualizes algorithms and lets users create and share custom graphs and trees.
• SPOJ Free
  • Online judge with thousands of programming problems.
• Stanford CS 97SI Free
  • Stanford's introduction to competitive programming with comprehensive lecture slides and practice problems.
• Topcoder Data Science Tutorials Free
  • Classic tutorials by Topcoder members covering algorithms and data structures used in competition.
• USA Computing Olympiad Free
  • USACO training pages with self-paced algorithmic problems to develop contest programming skills.
• USACO Guide Free
  • Curated learning path for competitive programming from bronze to platinum.
• USFCA Algorithm Visualizations Free
  • David Galles' interactive visualizations for sorting, graphs, trees, heaps and data structures.
• UVa Online Judge Free
  • Classic programming problems and contests.
• VisualAlgo Free
  • Interactive algorithm visualizations for sorting, graph, and data structure algorithms.
• William Fiset YouTube Free
  • Comprehensive YouTube channel covering almost all data structures and algorithms with animations.
• Binary Search Freemium
  • Collaborative coding problems and real-world interview questions.
• Brilliant - Computer Science Freemium
  • Interactive CS fundamentals including algorithms, logic, and cryptography.
• GeeksforGeeks - DSA Self Paced Freemium
  • Structured data structures and algorithms course with practice problems.
• HackerRank - Algorithms Freemium
  • Algorithm practice problems from warm-up to hard difficulty.
• InterviewBit Freemium
  • Interview preparation platform with curated problem sets.
• LeetCode - Explore Freemium
  • Curated learning paths for data structures and algorithms.
• LeetCode Daily Freemium
  • Daily coding challenge with 3000+ problems.
• LintCode Freemium
  • Coding interview practice with 1000+ algorithm problems.

SQL & Database Practice

• CodeChef SQL Practice Free
  • Interactive SQL course with topic-wise case studies covering JOINs, subqueries, and aggregate functions.
• DB-Fiddle Free
  • Free online SQL database playground.
• DBeaver Free
  • Free multi-platform database tool supporting all popular databases for querying and administration.
• Google BigQuery Sandbox Free
  • Free cloud platform for practicing SQL on real-world public datasets with just a Google account.
• GUVI SQLKata Free
  • Structured SQL coding challenges based on real company scenarios with auto-grading and rewards.
• Hackr.io SQL Tutorials Free
  • Community-curated directory of the best SQL tutorials and courses for learning SQL.
• Learn SQL Online Free
  • Interactive SQL tutorials for beginners with hands-on exercises.
• Mode SQL Tutorial Free
  • SQL analytics tutorial for data analysis.
• Oracle Live SQL Free
  • Oracle's free online SQL workspace for running SQL and PL/SQL scripts on live Oracle databases.
• pgExercises Free
  • PostgreSQL exercises from basic to advanced with a real database schema.
• Practice-SQL Free
  • Free SQL practice platform with online terminal offering easy, medium, and hard query challenges.
• Scaler SQL Topics Free
  • Curated interactive learning space for mastering SQL skills with basic and advanced concepts.
• Schemaverse Free
  • SQL-based space strategy game.
• Select Star SQL Free
  • Free SQL tutorial based on real datasets.
• SQL Drills Free
  • 300+ free SQL exercises organized by difficulty covering SELECT, JOINs, GROUP BY, and subqueries.
• SQL Practice Free
  • Browser-based SQL practice with instant query execution and results.
• SQL Practice Online Free
  • SQL playground supporting PostgreSQL, MySQL, SQL Server with FAANG-style interview questions.
• SQL Query Lab Free
  • Practice SQL queries against in-browser SQLite databases with 74 exercises across real schemas.
• SQL Zoo Free
  • Interactive SQL tutorials and exercises.
• SQLbolt Free
  • Interactive SQL lessons and exercises.
• SQLBolt Interactive Free
  • Interactive SQL tutorial with exercises built into the browser.
• SQLFiddle Free
  • Online tool for testing SQL queries.
• SQLite Online Free
  • Online SQL IDE supporting SQLite, PostgreSQL, MySQL, SQL Server with import and charting.
• SQLPractice.in Free
  • Free online SQL compiler with real-world interview questions from top tech companies.
• SQLTeaching Free
  • Interactive SQL lessons with real-time query execution in the browser.
• W3Schools SQL Free
  • SQL tutorial with interactive exercises.
• DataLemur Freemium
  • SQL interview questions from top tech companies with solutions.
• EverSQL Freemium
  • AI-powered SQL query optimization tool that automatically analyzes and tunes slow SQL queries.
• HackerRank - SQL Freemium
  • SQL practice problems from basic to advanced.
• LearnSQL.com Freemium
  • Interactive SQL learning platform with step-by-step courses and real-time feedback across databases.
• LeetCode - SQL Freemium
  • SQL interview problems and solutions.
• SQL Academy Freemium
  • Learn SQL with interactive lessons and 130+ practice tasks with MySQL and PostgreSQL.
• StrataScratch Freemium
  • Real SQL and Python interview questions from FAANG companies.
• SQL Habit Paid
  • Story-driven SQL and data analysis course with mock interviews simulating real product challenges.

Programming Quizzes & MCQs

• Code Conquest Coding Quizzes Free
  • Free multiple-choice coding quizzes with 10 random questions per quiz across languages.
• CoderMantra Coding Quiz Free
  • Free MCQ coding quizzes for Python, Java, C, SQL, and more for interview preparation.
• CoderStar Coding Quizzes Free
  • Interactive real-world coding quizzes across multiple languages and topic-based problem sets.
• CodingBison Free
  • Programming tutorials with coding problems and exercises for Python, Java, C, JavaScript, and data structures.
• CodingTests.online Free
  • Free coding tests for Python, Java, C#, and JavaScript to prepare for developer interviews.
• CppQuiz Free
  • Free interactive C++ quiz with 189+ questions based on the C++ standard to test deep language knowledge.
• DeveloperQuiz Free
  • Learn to Code RPG Quiz Practice with 1200+ Questions
• ExamVeda Programming MCQs Free
  • Programming MCQs for C, C++, Java, Python, JavaScript, PHP, and more with answers for competitive exams and interviews.
• GeeksforGeeks Quiz Hub Free
  • Topic-wise MCQs and mock tests covering C, algorithms, data structures, networks, and aptitude.
• Guru99 Quizzes Free
  • Programming tutorials with interview questions and quizzes for Java, Python, SQL, Selenium, and testing.
• IncludeHelp MCQs Free
  • Programming MCQs and aptitude questions for C, C++, Java, Python, JavaScript, PHP, and CS subjects with answers.
• IndiaBIX Programming MCQs Free
  • Programming MCQs and interview questions with detailed answers and explanations for many languages.
• InterviewBit MCQs Free
  • Technical interview MCQs for Java, Python, C, C++, JavaScript, DBMS, and data structures with answers.
• Java2s Tutorials & Quizzes Free
  • Programming tutorials with quiz sections for Java, C, C++, C#, JavaScript, Python, PHP, and SQL with mock exams.
• Learn Programming Quiz Free
  • Interactive coding quizzes in Python, JavaScript, Java, and C++ with progress tracking.
• LearnCpp Quizzes Free
  • Free C++ tutorial with chapter-wise quizzes at the end of each chapter to test your understanding of concepts.
• MCQs.dev Free
  • Free and open-source programming and computer science MCQs across 55+ languages.
• MyCodeSkills Free
  • 10,000+ free coding MCQs with answers and explanations for Java, Python, SQL, and React.
• Placement Preparation MCQs Free
  • Extensive technical MCQs covering programming and computer science topics for placement and interview prep.
• Practice Python Free
  • 40+ beginner Python exercises with solutions to practice and test your Python programming skills.
• ProgQuiz Free
  • Daily programming quizzes and challenges for Python, JavaScript, Java, and more languages.
• ProProfs Programming Quizzes Free
  • Community-created programming quizzes covering Java, Python, PHP, Ruby, and general computer programming concepts.
• PSkills Free
  • Online programming tests in C, Java, .NET, PHP, and HTML with explanations and interview Q&A.
• PYnative Python Quizzes Free
  • 16 topic-wise Python MCQ quizzes with 540+ questions and detailed explanations for each answer.
• Solviyo Programming Quizzes Free
  • Interactive programming quizzes in Python, JavaScript, Java, C++, Go, Kotlin, and HTML.
• TechBeamers Python Quizzes Free
  • Python quizzes and MCQs covering basics, data structures, OOP, multithreading, and DSA for interview preparation.
• TechieLearn Quiz Free
  • Free interactive programming quizzes across 60+ subjects including JS, Python, React, SQL, and DevOps.
• TutorialRide Online Tests Free
  • Online MCQ tests for Java, C, C++, HTML, CSS, JavaScript, SQL, OOP, data structures, and operating systems.
• TutorialsPoint Java Quiz Free
  • Free Core Java MCQ quiz with multiple choice questions and instant answers to test your Java knowledge.
• TutorialsTeacher Online Tests Free
  • Online tests and MCQs for Python, JavaScript, C#, SQL, LINQ, Angular, Node.js, and other web technologies.
• W3resource Quizzes Free
  • Free online quizzes for Python, JavaScript, Java, C, C++, SQL, and many more programming languages and technologies.
• W3Schools Quizzes Free
  • Multiple choice quizzes for many programming languages and web technologies to test your knowledge.
• Java-Success Freemium
  • 800+ Java and Big Data interview Q&As with code, diagrams, and scenarios for developers and engineers.
• Learneroo Freemium
  • Learn programming by solving challenges in Java, Python, algorithms, and web development in the browser.
• Programiz Freemium
  • Programming tutorials with challenges and quizzes for Python, JavaScript, Java, C, C++, SQL, and DSA.
• Real Python Quizzes Freemium
  • Interactive Python quizzes with scored questions covering basics to advanced topics including web dev and data science.
• Scaler Topics Challenges Freemium
  • Programming tutorials with challenges and MCQs for Python, Java, C++, JavaScript, SQL, DSA, and DBMS.