Geological Storage of CO₂ and H₂: A Bibliometric Synthesis of General and Laboratory-Scale Research Evolution. Underground gas storage is a cornerstone technology for addressing climate change and advancing the clean energy transition. By managing greenhouse gas emissions and enhancing energy system resilience, it supports global sustainability goals. This study presents a comparative bibliometric analysis and review of geological CO₂ and H₂ storage research based on publications indexed in Scopus till December 31, 2024. For CO₂ storage, 21,996 publications were identified, including 8447 focused on laboratory-scale experiments (38.4%), with sandstones being the most studied lithology. Key topics include monitoring (1.25%), enhanced oil recovery (1.24%) and injection (0.99%), whereas key parameters that govern CO₂–rock–fluid interactions are porosity, permeability, adsorption–desorption and density. H₂ storage research, comprising 4229 publications, 1541 of which are related to laboratory-scale experiments (36.43%), has exhibited exponential growth since 2020. Major areas of focus include CO₂-related studies (1.8%), wettability (1.29%) and cushion gas (0.97%); and key parameters are porosity and permeability, together with geomechanical and microbial parameters. Across all laboratory-scale studies, pH measurements, scanning electron microscopy (SEM), computed tomography (CT), x-ray diffraction (XRD) and nuclear magnetic resonance (NMR) are the most frequently applied techniques to characterize fluid–rock interactions. A total of 546 papers address combined laboratory studies on CO₂ and H₂ storage. The co-occurrence analysis of keywords within these studies highlights emerging thematic interconnections and research synergies between both storage technologies. Results of both research domains underscore the critical role of experimental methodologies in advancing understanding of reservoir behaviour and storage capacity. These findings highlight the need for interdisciplinary innovation and international collaboration to overcome technical challenges and accelerate the deployment of geological gas storage applications.