An ISSN is a unique identifier for a journal. You can read more about ISSN's in our article titled What is an ISSN (International Standard Serial Number)?
This page enables you to make certain checks about an ISSN (i.e. a journal). At the moment, the page checks that the ISSN is recognized by ISSN (itself), DOAJ (Directory of Open Access Journals) and COPE (Committee on Publications Ethics).
You need provide the ISSN as part of the URL. That is; https://predatory-publishing.com/ISSNCheck/?issn=nnnn-mmmm, where "nnnn-mmmm" is an ISSN.
For example https://predatory-publishing.com/ISSNCheck/?issn=1234-5678 is a valid URL, although that journal does not exist. If you click the link, take a look at the URL, and you can see the ISSN is provided at the end of the URL.
The information we display below is brought to you in good faith but, if you are going to use this data to make important decisions, you should check the data yourself. This is easy to do.