- Advent of Code - An Advent calendar of daily programming puzzles from December 1st to the 25th for various skill sets and skill levels that you can solve in any programming language.
- aGupieWare - Offers online resources to learn how to code and master computer science.
- BitDegree- A great place to learn to code for free.
- Bento - Curates free coding classes and tutorials and turns them into easy-to-follow curriculums.
- CodeChef - An educational program and competitive programming community of programmers from across the globe.
- Code Conquest - This free online guide offers various resources to become a professional coder.
- Codewars - A coding practice site for all programmers where you can learn various programming languages.
- CodinGame - An online platform for developers, allowing them to play with programming with increasingly difficult puzzles, to learn to code better, supporting twenty-five programming languages, and to compete in multiplayer programming contests involving timed artificial intelligence, or code golf challenges.
- CodeForces - A website that hosts competitive programming contests.
- Codecademy - It offers free and paid courses on a wide range of programming subjects.
- Codeasy - Designed for those with no programming experience, using an adventure story about saving the world from a machine invasion.
- Code Avengers - A primarily paid platform, but it also offers free courses for learning to code.
- Dash by General Assembly- Coding bootcamp and digital learning platform. With this site, users can learn to code for free by creating basic online projects on their web browser.
- Edabit - This free online learning platform uses a hands-on approach to help people learn to code.
- freeCodeCamp - One of the most trusted platforms to learn to code for free
- Google Developers - Help users build applications or improve their web projects using Google’s technology.
- GeeksforGeeks - Platforms for free content on learning about numerous programming languages and other coding-related topics.
- Hackr.io - Aggregate courses from many providers to make it easy to find the best courses on almost any subject, wherever they exist on the web.
- HackerRank - Solve code challenges to prepare for programming interviews.
- HackerEarth - Helps organisations with their technical hiring needs, technical skill assessment and remote video interviewing.
- InterviewBit - A platform to learn skills that you need for technology jobs. whether you are a fresh college graduate or a working professional.
- LeetCode - the best platform to enhance your skills, expand your knowledge and prepare for technical interviews.
- ProjectEuler – A dedicated to a series of computational problems intended to be solved with computer programs.
- Pluralsight - A primarily premium platform that offers free programming courses and tutorials.
- Spoj - allows advanced users to organize contests under their own rules and a forum where programmers can discuss how to solve a particular problem.
- Topcoder - An open global community of designers, developers, data scientists, and competitive programmers.
- Upskill - A freemium coding bootcamp known for its beginner-friendly video lectures, make complex programming concepts much easier to understand by using jargon-less and straightforward language.
- VisuAlgo – Learn data structures and algorithms through dynamic interactive visualizations (visualization component), and an automated assessment system (training component)
- W3Schools - Offers some of the best resources for developers to learn content for free.