Expansive soils pose significant challenges to various engineering applications due to their volume-changing behavior in response to moisture fluctuations. The expansive nature of these soils results in undesirable consequences such as swelling, shrinkage, and loss of structural integrity, affecting the stability of foundations, pavements, tunneling, etc. Globally, infrastructure has faced both short-term and long-term damage from these expansive soils. Numerous mechanical and chemical techniques have been extensively employed to mitigate the extent of soil expansiveness and the resultant damages. This paper presents an exploration, focusing on the comparative evaluation of two distinct stabilization approaches, i.e., lime treatment and alkali-activation treatment. Lime, as a traditional calcium-based stabilizer, engages in pozzolanic reactions to enhance soil stability. In contrast, alkali-activation treatment, a non-calcium-based technique, employs geopolymers to achieve analogous results. This investigation examines and compares the effects of both methods on reducing the swelling potential of expansive soils. Their performances are evaluated and discussed through swelling tests as well as corresponding microstructure analyses.