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).
Sadie
Sadie is down from its peak but still widely used. All-time it's been given to 149,922 U.S. babies, the 199th most common name by sound today, peaking at 4,871 in 2014, with 4,168 in 2025.
Sadie has no common alternate spellings by sound.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).