The major tool for this is Compare Journals, which compares up to 10 journals on CiteScore, SCImago journal rank by year, and SNIP, Source Normalised Impact per Publication.
Alternatively, you can get a quick snapshot for a particular journal by clicking on the journal name in the list of results of a search. You will be presented with the CiteScore, SCImago journal rank, and SNIP for the journal in question.
The Compare journals function in Scopus allows you to compare up to 10 journals and view various metrics in either graphical or tabular format:
"The SCImago Journal & Country Rank is a portal that includes the journals and country scientific indicators developed from the information contained in the Scopus® database ... This platform takes its name from the SCImago Journal Rank (SJR) indicator, developed by SCImago from the widely known algorithm Google PageRank™. This indicator shows the visibility of the journals contained in the Scopus® database from 1996."
"CWTS Journal Indicators provides free access to bibliometric indicators on scientific journals. The indicators have been calculated by Leiden University’s Centre for Science and Technology Studies (CWTS) based on the Scopus bibliographic database produced by Elsevier. Indicators are available for over 20,000 journals indexed in the Scopus database."
The two main indicators available are: