Eight great sites that offer online classes

If you’ve already streamed your favorite series for the third time, and you’ve hit a wall with your latest game, what should you do while you’re sheltering at home? Well, maybe pick up a new skill or hobby by taking a class.

There is a huge number of courses available online, from coding to history to languages, and a lot of different resources to choose from. Below, we’ve listed some of the major sites where you can find online classes, some you can attend in real time and others you can pop into at your leisure.

While many of these websites charge fees for memberships or specific classes, we’ve indicated which ones also offer free courses.

Code Academy offers courses on computer science, data science, and web development. You can sign up for the free plan, which gives you access to 25 courses, or you can opt for the Pro level for $19.99 a month, which comes with 65 courses as well as exercises, quizzes, and projects. Signing up for the Pro subscription also gets you access to Code Academy’s “paths,” class sequences that can help you prepare for a specific career or learn a specific skill.

Sample Courses: Introduction to HTML; Make a Website; Learn SQL

Coursera is one of the most well-known platforms for online classes, and its catalog is so extensive that you could even complete a degree on the site. It hosts courses from institutions and organizations, including Google, Stanford, and, more recently, MoMA in a broad range of subjects. You can join Coursera for free, and you can audit many of the classes for free, but you will have to pay if you want a course certificate, to submit assignments, or get grades. Some courses have a one-time fee, or you can pay a monthly subscription fee to access a related set of courses, called a “Specialization.” You can also pay a yearly subscription fee for Coursera Plus, which gives you access to and allows you to earn certificates for most of Coursera’s classes. (Here’s a full list.)

Sample Courses: Yale’s The Science of Well-Being; Stanford’s Machine Learning; MoMA’s Seeing through Photographs

edX was founded by Harvard and MIT, and it partners with other universities, including Berkeley, Brown, and Cornell, to provide courses online. The site has a broad variety of classes, including subjects that range from data sciences to the arts and humanities. Most courses are available for free, but you will typically have to pay between $50 and $300 to be able to submit assignments for feedback and to receive a certificate.

Sample Courses: Berkeley’s The Science of Happiness; NYU’s Basics of Computing and Programming; Harvard’s Modern Masterpieces of World Literature

If you really want to take a Harvard course, the university lists its online courses on its website. (These listings link to edX, which is where you can take the class.) Harvard offers courses on a variety of subjects; the classes go from two to over 12 weeks. The site lets you easily filter the results to find free courses. The paid courses cost anywhere from $30 to over $3,000, and if you want a certificate to prove you’ve finished a free course, that will come with an additional fee. (The ones we looked at ranged from $49 to $169.)

Sample Courses: Introduction to Computer Science; Religion, Conflict and Peace; Science & Cooking: From Haute Cuisine to Soft Matter Science

Kadenze offers courses on art and technology — everything from graphic design to preparing for a career in media to learning an instrument. While some of these courses are created by Kadenze, others come from institutions such as the Maryland Institute College of Art, Berklee College of Music, Stanford, and Columbia. You can sign up for the free subscription, which allows you to enroll in the courses, but you can’t submit assignments or receive college credit. To get access to additional course content, submit assignments, and receive grades, you can sign up for the Premium plan, which costs $20 a month. In order to earn credit for the course, you’ll have to pay $300 per credit on top of that monthly subscription fee.

Sample Courses: Gender, Race and Technology; Careers in Media Technology; Guitar for Beginners

Khan Academy is a nonprofit designed as a resource to support students from preschool through high school, and it offers all of its courses for free. It includes courses in math, science, and engineering, as well as in the arts and humanities. It does offer some courses that may be useful for people who are no longer students, such as career advice, entrepreneurship, personal finance, and MCAT and LSAT test prep.

Sample Courses: Navigate your career; Algorithms; Statistics and probability

Like Kadenze, Skillshare offers courses mainly in the arts, with classes in animation, music, photography, and creative writing, but also offers instruction in business, technology, and marketing. Its course catalog is intended to encourage creativity and help people build creative skills into careers. Skillshare has a number of courses available for free, but to access the full catalog of courses, you have to pay for a premium membership of either $19 a month or $99 a year.

Sample Courses: How to Make a Podcast; Building Your Freelance Business; Demystifying Graphic Design

Udemy has a collection of 100,000 courses available, most of which tend to be career-focused, with subjects such as finance and accounting, office productivity, programming, and marketing. However, Udemy also offers courses on subjects such as music, lifestyle, personal development, and health and fitness. While most of Udemy’s courses have a fee associated, you can filter your results to see the courses Udemy offers for free; however, you won’t earn a certificate or be able to communicate with the instructor like you would in a paid course.

Sample Courses: Best Practices for Working Remotely; Getting Started with Playing Guitar; Free Digital Marketing Basics Course