Jesper sits next to 4 phonetic neighbors — Jasper, Jesse, and Casper are the closest matches by sound. Most share Jesper's Dutch-origin cluster, so the rhythm and vowel shape carry across the list.
You searched for names like
"treasurer, keeper of treasure"
"peaceful will"
"lotus flower, love"
"bearer of Christ, Christ-carrier"
"Thor's stone"
"holy heir"
"rich in friendship"
"from Britain, Briton"
"fury, divine madness, inspiration"
"wealthy, God's gift"
"hill, ridge, small summit"
"Yahweh has been gracious"
"peaceful ruler"
"protected dwelling"
"From; of the fen or marshland"
"resolute, bright"
Similar sound: These names share phonetic patterns with Jesper — similar vowel sounds, consonant clusters, or rhythm.
Shared roots: Several names on this list have Persian via Old French origins, giving them the same cultural heritage as Jesper.
Rhythm: Jesper is a 2-syllable name. Names with the same syllable count tend to feel interchangeable when you're narrowing your list.