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).
Kylo has been climbing in recent years. All-time it's been given to 5,431 U.S. babies, the 784th most common name by sound today, peaking at 883 in 2024, with 806 in 2025.
Kylo has no common alternate spellings by sound.
Source: U.S. Social Security Administration, “National data” baby-names files (1880–2025).