There is a growing number of "predatory publishers" who claim to be legitimate open access publishers. Predatory publishers are opportunistic entities that exploit researchers by charging fees while providing little or none of their promised services and benefits.
If you've found an open access journal relevant to your research and want to ensure its quality, check if the journal is included in the Directory of Open Access Journals (DOAJ) and see if the publisher is a member of the Open Access Scholarly Publishers Association (OASPA). Other evaluation criteria you might want to consider include the journal's profit model, peer review process, journal metrics and impact factor, and the credentials of the editorial board and previously published authors.
How Open Is It?
The “HowOpenIsIt?” Open Access Guide helps authors compare and contract journal policies on six fundamental aspects of open access: reader rights, reuse rights, copyrights, author posting rights, automatic posting, and machine readability.