CK-12 is described as 'Foundation provides a library of free online textbooks, videos, exercises, flashcards, and real world examples for over 5000 concepts from arithmetic to physics, engineering, and history. Our vision is to help you learn what you want, when you want, at your own pace' and is a online education service in the education & reference category. There are more than 10 alternatives to CK-12, not only websites but also apps for Android, iPhone, iPad and Android Tablet. The best CK-12 alternative is Khan Academy, which is free. Other great sites and apps similar to CK-12 are Tutorwise, Pocket Scholar, Engineer4Free and Learnamic.
Khan Academy is not-for-profit with the goal of changing education for the better by providing a free world-class education to anyone anywhere.
Khan Academy is the most popular Web-based, Android, iPhone & iPad alternative to CK-12.
Khan Academy is the most popular free alternative to CK-12.
An online teaching platform designed to help learners of all levels become confident and effective tutors. It offers 30 practical, interactive lessons covering topics such as identifying your teaching style, understanding how learners learn, delivering clear explanations...
Pocket Scholar is a science-learning platform centered around breaking down complicated science topics into smaller chunks that makes them easier to understand. We believe in a future where everyone has access to high quality, college level content that they actually can...
Pocket Scholar is the most popular commercial alternative to CK-12.
Engineer4Free is a tutorial site where anyone can learn university level engineering for free. Engineer4Free has made hundreds of YouTube tutorials and organized them into several courses ranging from Calculus to Project Management to Structural Analysis.
Search thousands of free and paid K-12 resources (apps, books, online courses, YouTube videos, whatever!) to find the right one for you, your kids, and your budget.
Start learning without distractions. Join thousands of focused learners who choose quality over quantity. Always free, always focused.
Grok Learning is the most popular Open Source alternative to CK-12.
NCERT solutions for class 6 - 10 maths and science with detailed solutions to each and every question covered in these NCERT books.
Eureka.in NSES app is specially designed for student and teachers dedicatedly aligned with the National Science Education Standard for USA.
Sunlight is a platform for companies looking to grow a highly engaging learning culture at work by empowering your team to access any course, book, or event in the world.
companies vs. schools — totally different
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Engineer4Free is for college students, not for K-12. These are totally different products