Geopolymer foams, as a new type of potential eco-friendly building material, are increasingly being discussed in the literature. This study reports the synthesis and characterization of geopolymer foams using hydrogen peroxide (H2O2) solution as pore-forming agent and oil as the stabilizing agent. The geopolymer foams with low bulk densities (0.37<ρb<0.74g/cm3), low thermal conductivities (0.11<λ<0.17W/(m.K)), high porosity (66<p<83 vol%), and acceptable compressive strength (0.3<σ<11.6MPa) were successfully fabricated at appropriate conditions. Factors that influence the insulating, mechanical, porous, and microstructural properties were investigated. It was found that the content of the stabilizing agent and the blowing agent had a significant influence on the porous structure and associated foam performance.