Solid line = floor (spellings that unambiguously belong to the group). Shaded band up to the dashed edge = ceiling (the most it could reach if every ambiguous spelling counted here).
Alexis is now well below its former popularity. All-time it's been given to 436,051 U.S. babies, the 533rd most common name by sound today, peaking at 23,990 in 1998, with 1,146 in 2025.
By sound, Alexis also includes the spellings Alexus, Alexys.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).