Alloys with melting points < 150 degrees C are required for the development of flexible consumer devices. While the eutectic In-48Sn alloy is a promising candidate for these applications, its low tensile strength and low creep resistance during solid-state aging are of concern. The addition of Ag can address this issue to some extent; however, the effect of added Ag on the properties of the alloy is not well understood. Here, we studied the effects of added xAg (x = 0.5, 1.0, 1.5 wt.%) on the fusion start temperature, microstructure, and mechanical properties of the In-Sn eutectic alloy and found that the fusion start temperature of the In-48Sn-xAg alloy was reduced to around 113 degrees C due to the ternary eutectic reaction of In-Sn-Ag, in which epsilon-AgIn2 only formed in the In-48Sn-xAg alloys. In addition, smaller beta-In3Sn and gamma-InSn4 phases were produced through the formation of epsilon-AgIn2, which affected the mechanical properties of the alloy. In-48Sn-1.5Ag, with the smallest grains, exhibited the highest tensile strength of 12.5 MPa via boundary strengthening. In-48Sn-1.5Ag fractured in transgranular mode, which is different from the intergranular fracturing of the eutectic alloy with relatively large grains. Conversely, In-48Sn-0.5Ag, with the highest soft-beta-In3Sn/hard-gamma-InSn4 ratio, showed the longest elongation of 64%, which is twice that of the eutectic In-48Sn alloy.