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).
Malachi has been climbing in recent years. All-time it's been given to 91,769 U.S. babies, the 160th most common name by sound today, peaking at 4,641 in 2025, with 4,641 in 2025.
By sound, Malachi also includes the spellings Malakai, Malaki, Malakhi.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).