Video created by University of Manitoba's Libraries.
While no one characteristic is definitive of a predatory journal or conference, here are a list of things that, when taken together, may point to a journal or conference being predatory in nature.
Unusual communications:
Emails or other correspondence are written in an awkward style and/or contain a large number of typographical errors.
Correspondence contains unusual vocabulary or appears to have been run through translation software.
The offer sounds too good to be true.
Journal or Conference Organizer Name:
The journal title or conference organizer's name is similar to a known, reputable journal or conference.
The title contains vague, but prestigious sounding words.
Website:
The Website is very similar to a legitimate organization's, perhaps having a different domain
The Website is amateurish in appearance with poor layout, typos, pop-up ads, etc.
The About Us page is either missing, or contains insufficient or contradictory information.
Contact information is either missing, insufficient, or contains broken links.
There is unclear, or falsely claimed affiliation with a well known, reputable organization.
The same publisher produces journals or conferences that are very broad in scope, and produces journals or conferences in a wide range of unrelated academic fields.
Editors or board members are from all over the world, have no, or insufficient academic credentials, or are unaware that the organization is claiming affiliation with them.
Metrics and Indexing:
The journal lacks an ISSN, or its articles or proceedings lack DOIs.
The organization lacks metrics, or uses metrics that are similar sounding to established metrics.
The journal impact factor cannot be verified using Journal Citation Reports.
The journal falsely claims to be indexed, e.g. in DOAJ.
The journal is not listed in a reputable source, such as Ulrich's Periodical Directory.
Article Processing and Peer Review:
There is a lack of clear instruction for submissions.
There is a lack of transparency regarding article processing fees.
Article processing fees seem too low when compared with known reputable organizations.
The peer review process is not adequately explained.
The peer review process is very fast, or non-existent.
Negative Reputation:
The organization is listed on Beall's List or Cabell's Blacklist.
Ultimately, judging whether an organization is predatory or not is often a matter of intuition. If, after doing some research, an organization seems fishy, it probably is.