Up to 4 names on one shared scale. The link in your address bar holds the whole comparison, so you can send it to someone and they’ll see exactly this.
Cal boy
Cal
One shared vertical scale, 0 to 324 per million babies of each name’s own sex. Comparing a girls’ name with a boys’ name compares two different cohorts — the shapes are comparable, the heights less so. Gaps are years with fewer than five births.