Google Scholar provides a journal ranking based on the number of citations that papers receive. The rankings are based on the h5-index and the h5-median.
This is a free ranking that is generated automatically by Google. The citations may not be as well curated as in other metrics databases. The advantage of Google Scholar is that it will have data for journals that are not included in other databases.
The h5-index is the largest number h such that h articles published in the journal between 2012 and 2016 (for 2017) have at least h citations each. This means that, in the example below, for papers in the Journal of Vertebrate Paleontology, 25 papers received at least 25 citations between 2012 and 2016. If you look at the same value for Nature, 366 articles received at least 366 citations over this time period.
The h5-median for a publication is the median number of citations for the articles that make up its h5-index.
You can use the Scopus Journal Analyzer tool to compare some important metrics such as CiteScore, SJR, SNIP, and the number of documents that are not cited, between the journals on your shortlist. The tool is available as part of the University of Reading's subscription to Scopus.
You can compare up to 10 different sources and then view the CiteScore, SJR and SNIP metrics for each journal as a graph or as a table. Looking at the number of papers that are never cited in each source can be interesting (use the % not cited tab) - it is best to submit to a journal that others read and cite regularly.
Look at the mix of item types in your selected journals using the %reviews tab. Some journals have a clear mandate to publish a lot of review articles and may have this in their title. However, some new and some less reputable journals may publish lots of review articles in order to artificially boost their citations and other metrics.
There is an option to export the data in chart or table form using the export button at the top of the page.
Example plot of SJR over time for a group of journals in the same subject area. The names of the journals have been redacted to preserve the confidentiality of the data.