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"
"eternal king, pure lineage"
"faithful one"
"desiring peace, will and peace"
"strength, exalted one"
"From; of the fen or marshland"
"man from Lucania"
"anointed one who carries"
"ancestor's relic, descendant"
"counsel, advice"
"peaceful ruler"
"hill, ridge, small summit"
"protected dwelling"
"resolute, bright"
"beautiful (phonetic usage)"
"peaceful ruler"
"rich in friendship"
"valley"
"wealthy, God's gift"
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.