If a journal take article processing fee then does that mean the journal is predatory? or there are some other criteria to tell a journal as predatory?
If a journal requires "Article Processing fee" does that make it a predatory journal? [duplicate]
1This answers your 2nd question: academia.stackexchange.com/questions/83764/…– AllureApr 27, 2020 at 23:38
No, not all journals that charge to publish are predatory journals. Some genuine open access journals charge article processing fees. For example, the journals by Copernicus, by the European Geophysical Union (EGU), charge moderate article processing fees. These cover the costs of the publisher, which then makes the articles available open access free of charge.
To label a journal as predatory you need other (additional) criteria.
4Some journals charge a "page fee" even when open access doesn't happen. Costs need to be covered somehow if a journal is to remain viable.– BuffyApr 27, 2020 at 12:58