There are many free online learning platforms available that offer courses, tutorials, and other resources for people to learn a variety of skills. Here are the 40 most popular ones:

Coursera: Offers courses from top universities and institutions around the world. Many courses are free, while others require a fee to access graded assignments and a certificate of completion.

edX: Provides courses from universities such as Harvard, MIT, and Berkeley, as well as professional training and certificate programs. Most courses are free to audit, while others require a fee to access graded assignments and certificates.

Khan Academy: Provides free online courses, video lectures, and practice exercises in a wide range of subjects, including math, science, economics, and humanities.

Udemy: Offers a wide range of courses, including programming, business, design, and personal development. While many courses are paid, there are also numerous free courses available.

Codecademy: Focuses on teaching coding and programming skills, with interactive coding lessons and projects. While most courses are paid, there are also some free courses available.

MIT OpenCourseWare: Offers free access to courses from the Massachusetts Institute of Technology, including lecture notes, assignments, and exams.

Stanford Online: Provides free online courses and materials from Stanford University, including videos, lectures, and course materials.

FutureLearn: Offers a wide range of free online courses from top universities and organizations around the world, with opportunities to earn certificates or academic credit for a fee.

OpenLearn: Provides free courses and resources from the Open University in the UK, covering a wide range of subjects, including arts, science, and technology.

More learning platforms:

Google Digital Garage: Offers free courses on digital marketing, data analytics, coding, and other digital skills. The platform is developed by Google and offers certifications.

Alison: Offers free courses in a wide range of subjects, including IT, business, healthcare, and languages. The platform offers certifications for a fee.

Duolingo: Provides free language courses in over 40 languages, with a focus on gamification and interactive learning.

Rosetta Stone: Offers a free trial of its language learning software, which uses a natural immersion approach to language learning.

YouTube: Offers a vast library of educational videos on a wide range of topics, from science and technology to art and music.

Academic Earth: Provides free online courses from top universities in the US, including Yale, Stanford, and MIT.

Harvard Online Learning: Provides free online courses from Harvard University, covering a range of subjects from computer science to psychology.

Open Culture: Provides free online courses, audio books, and eBooks from top universities and cultural institutions around the world.

Saylor Academy: Offers free courses and resources in a wide range of subjects, including business, education, and science.

Ted-Ed: Provides free educational videos on a range of subjects, with a focus on short animated lessons.

LinkedIn Learning: Provides access to a large library of video courses and tutorials, with a focus on professional development and career skills. While the platform requires a paid subscription, a one-month free trial is available.

Skillshare: Offers thousands of free classes and tutorials in a variety of subjects, including design, marketing, and photography. Some classes are free, while others require a paid subscription.

Learn a Language: Provides free language learning resources and courses for a variety of languages, including French, German, Spanish, and Chinese.

Stanford Engineering Everywhere: Offers free online courses and resources in engineering, including computer science, electrical engineering, and artificial intelligence.

MIT Open Learning Library: Provides free access to MIT course materials, including lecture notes, assignments, and exams, across a range of subjects.

Open Yale Courses: Provides free online courses and resources from Yale University, including video lectures, transcripts, and other materials.

Google Analytics Academy: Offers free courses and resources to help people learn how to use Google Analytics to analyze website traffic and user behavior.

Canvas Network: Provides free online courses and resources from universities, institutions, and organizations around the world, across a range of subjects.

HarvardX: Offers free online courses and resources from Harvard University, including video lectures, interactive learning tools, and discussion forums.

Microsoft Learn: Provides free online courses and resources to help people learn Microsoft technologies and tools, including Azure, Power BI, and Dynamics 365.

Adobe Creative Cloud Tutorials: Offers free tutorials and courses to help people learn how to use Adobe Creative Cloud tools, including Photoshop, Illustrator, and InDesign.

FutureProof: Provides free online courses and resources for people looking to upskill or reskill in a range of industries, including tech, healthcare, and finance.

Learn UX: Offers free online courses and resources to help people learn about user experience (UX) design, including courses on design thinking, wireframing, and prototyping.

Class Central: Provides a comprehensive directory of free online courses from universities and institutions around the world, searchable by subject and provider.

OpenStax: Offers free, peer-reviewed, and openly-licensed textbooks and resources for college and high school students, covering a range of subjects.

LinkedIn Learning Paths: Offers curated collections of free online courses on specific topics, such as leadership, data science, and project management.

iversity: Provides free online courses and resources from top universities and institutions across Europe, covering a wide range of subjects.

TypingClub: Offers free online typing lessons and games to help people improve their typing speed and accuracy.

GCF LearnFree: Provides free online courses and tutorials on a range of subjects, including technology, math, and reading.

Pluralsight: Offers a limited selection of free courses and resources for people looking to learn new skills in technology and creative fields.

HubSpot Academy: Provides free courses and certifications on marketing, sales, and customer service, as well as free resources on topics such as SEO and social media.

These platforms offer a wide range of learning opportunities across different subjects and fields, so you can find a platform that suits your interests and goals.