Many Coursera courses are available to audit for free. Some courses, including all course materials and assessments can be completed for free, while others have assessment items and, occasionally, supplementary course materials, behind a paywall. Certificates are not available without paying.
Individual courses and Specializations cost varying amounts. The price will appear when you click on the blue Enroll button on the left of the Coursera course information page. You must be logged into Coursera to see the pricing information. Courses may be available either on a subscription basis or for individual purchase.
Many Specializations run on a subscription basis costing between US$39-79 per month. Most offer a 7-day free trial, after which you will be billed. If you cancel within the free trial time, you will not be billed, unless you have completed a course and received your certificate.