Journal metrics measure, compare, and often rank research and scholarly publications. They can also be referred to as journal rankings, journal importance, or a journal’s impact. Journal metrics allow scholars and researchers to compare scholarly periodicals (Adopted from University Library, Evaluating Journals Using Journal Metrics: Overview).
The original citation impact metric is the Journal Impact Factor, created in the 1950s, and available through Thompson Reuters’ Journal Citation Reports. More recently, a variety of other free journal metrics have been created, including, SCILit, CiteScore, Google Scholar Metrics, SCImago Journal & Country Rank (SJR), and Source Normalized Impact per Paper (SNIP).