How to read the band →
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).
Alexa
Alexa is now well below its former popularity. All-time it's been given to 131,835 U.S. babies, the 1,169th most common name by sound today, peaking at 6,125 in 2006, with 243 in 2025.
Alexa has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).