1. Coursera – Offers a wide range of university-backed courses and certificates. Strong academic reputation.

  2. edX – Similar to Coursera, edX offers courses from universities and institutions. Some content is free.

  3. Udemy – User-generated courses with a broad selection. Not as academically rigorous but great for practical skills.

  4. LinkedIn Learning – Focuses on career-oriented skills, especially in business and tech. Good integration with LinkedIn profiles.

  5. Khan Academy – Free platform, especially strong for K-12 education and college prep. Math and science-focused.

  6. Pluralsight – Known for tech and IT skills, Pluralsight offers expert courses for developers and IT professionals.

  7. FutureLearn – Similar to Coursera and edX, with a wide range of professional and academic courses.

Creative and Professional Skills

  1. Skillshare – Good for creative skills like design, photography, and writing. Subscription-based.

  2. CreativeLive – Focuses on creative professionals, offering courses in photography, music, and design.

  3. 99designs – Not a traditional learning platform. It’s a marketplace for design work but can help designers build portfolios.

  4. Teachable – A platform for creating and selling courses. More for course creators than learners.

  5. MasterClass – Celebrity-led courses with insights from experts in fields like film, writing, and cooking.

  6. The Great Courses Plus – Offers lectures and courses on history, science, and personal development. Subscription-based.

Technology and Coding

  1. Codecademy – Great for beginners learning to code. Hands-on coding practice in a range of languages.

  2. Treehouse – Focuses on web development and coding with beginner to intermediate courses.

  3. Udacity – Specializes in tech skills and "nanodegrees," often in partnership with major tech companies.

  4. SoloLearn – Mobile-friendly, good for bite-sized coding lessons and a large community of learners.

  5. Skillcrush – Focuses on coding, web design, and development for beginners.

  6. MIT OpenCourseWare – Free, high-quality courses from MIT. Best for academically inclined learners.

Data Science and Analytics

  1. DataCamp – Specialized in data science and analytics. Offers practical hands-on exercises.

  2. Google Digital Garage – Free courses focused on digital marketing, data, and business skills.

Language Learning

  1. Rosetta Stone – Traditional language learning with a focus on immersion. Paid platform.

  2. Duolingo – Free language learning app, great for casual learners or beginners.

  3. Memrise – Combines language learning with memory techniques and real-world phrases.

Professional and Business Skills

  1. General Assembly – Offers in-depth boot camps and courses in coding, UX design, and business skills.

  2. HubSpot Academy – Specializes in marketing, sales, and customer service skills. Offers certifications.

  3. Alison – Free courses in a wide range of subjects, including business and tech. Certificates offered.

Niche Platforms

  1. Big Think – Offers short videos and articles from thought leaders. Not a course platform but good for insights.

  2. OpenClassrooms – Focuses on tech and career-oriented skills with mentorship options.

Summary: Best for Coding/Tech: Codecademy, Treehouse, Pluralsight, Udacity. Best for Academic Courses: Coursera, edX, MIT OpenCourseWare. Best for Creative Skills: Skillshare, CreativeLive, MasterClass. Best for Language Learning: Duolingo, Rosetta Stone, Memrise.