Abstract
In this paper, we present some alternative results concerning the uniqueness and Ulam-Hyers stability of solutions for a kind of psi-Hilfer fractional differential equations with time-varying delays. Under some updated criteria along with the generalized Gronwall inequality, the new constructive results have been established in the literature. The derived analysis has the ability to generalize and improve some other results from the literature. As an application, two typical examples are delineated to demonstrate the effectiveness of our theoretical results.