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).
Jax
Jax is now well below its former popularity. All-time it's been given to 28,626 U.S. babies, the 531st most common name by sound today, peaking at 2,092 in 2015, with 1,169 in 2025.
By sound, Jax also includes the spellings Jaxx. Spellings sometimes heard the same way: Jacques.
Rising
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).