The field cut of the Q1 list
Start from the directory's shape: 195 of its 329 venues are computer science, because that is the field this site was built for. Of the 172 Q1 journals in the directory, 48 are computer science titles. The other 147 CS venues are conferences on the tier ladder, which is the first thing to understand about publishing in this field: the journal list is the minority report. In computer science the flagship venues are conferences, and a Q1 journal list, however carefully built, covers only the journal half of the target map.
Why other Q1 lists count 120 and we count 48
List sites that crawl the full ranking databases report around 120 Q1 computer science journals, and SCImago's CS table runs to more than 2,600 journals across all quartiles. Those are censuses. This directory is a shortlist: 329 venues a researcher might plausibly target, chosen field by field. A census answers "what exists"; a shortlist answers "what should I consider", and confusing the two produces bad submission plans. Our 48 are the Q1 journals that survived the shortlist cut, each with its recorded metric in the directory: 310 of the 329 venues carry a recorded impact factor or CORE rank figure.
How to use a 48-title list
Read it as a filter, not a ranking. Note which of the 48 publish your subfield, check their turnaround reputation in your own community, and only then weigh the quartile. The Odds Checker exists for the next step: it prices a target list against an honest read of the paper, which is the step a bare list cannot do for you.
The full Q1 count, for reference
The companion count on this blog, Q1 Journals, Counted, walks the whole directory: 172 of 188 journals in Q1, the rest in Q2, and the conference ladder kept separate. Start there if your field is not computer science.