within minutes; in a few minutes
Used to indicate that something will happen or be completed in a short time, typically within a few minutes. Often appears in instructions, announcements, or descriptions of quick processes.
I'll be back within a few minutes.
This medicine starts working within minutes.
すぐに is a more general and common adverb meaning 'immediately' or 'right away', while 数分以内 specifically emphasizes a time frame of a few minutes.
間もなく is a slightly formal adverb meaning 'soon' or 'before long', without specifying an exact duration, unlike 数分以内 which sets a clear limit.
Compound of 数分 (a few minutes) + 以内 (within, inside). The phrase follows standard Sino-Japanese word formation patterns.