The name reached its all-time peak in 2008 with 3 births ranking #5545. STABLE Recent data shows the name is currently stable.
Kobi is usually used as a modern spelling related to Kobe, Koby or other Jacob-family short forms. Because similar spellings also overlap with other traditions, it is best treated as a mixed modern variant rather than pinned to one narrow source.
In practice, Kobi often travels with the same sound family as Kobe, Koby and Coby. That gives it a recognisable modern feel, but also means the exact origin can shift from one family to another.