Beall's lists on "Scholarly Open Access" (potential, possible, or probable predatory scholarly open-access publishers) are somewhat controversial but the webpages contain a wealth of information that is part of any journal or publisher investigation. You can at least find clues about the content that will help you make informed decisions. The website scholarlyoa.com was taken offline in 2017, but some persons have archived the content that was originally posted**. There are also a number of websites and publications aimed correct and incorrect information about content connected to Beall and his lists - be careful when searching for the concept of predatory journals.
** https://beallslist.weebly.com