It is free to join and study the majority of FutureLearn courses.
If you want you can upgrade your course to get additional benefits, like the ability to qualify for a certificate. You can find more information about this on the course page.
While most courses are offered with an option to learn for free, some premium courses are only offered on a paid-for basis. These courses are designed for professionals looking to advance their careers and learn with a smaller group of like-minded individuals.