What the blog covers
Each article answers one question that people ask about free online courses and cannot settle from a provider's marketing page: whether a certificate is really free, how an audit track works and when it ends, what a credential shows an employer, and how to start on a given platform without paying. The answers are drawn from the same course records and provider pages that feed the listings, and every article ends with the sources it was checked against.
Articles link to the courses they discuss, so a claim about a price, a length or a certificate can be checked against the course page here and, from there, against the provider. When a course record changes, the figures in the article change with it; sentences that can no longer be supported are removed rather than left stale.
Where to go from an article
Most articles sit beside a provider page: Harvard, MIT, Coursera and freeCodeCamp each have a guide under their ranking table that covers the same ground in less depth, with every listed course in one table. For the certificate question across all providers, the free certification courses page lists only courses whose certificate costs nothing, and free online courses with certificates shows the paid ones beside them with their stated prices.