In the present work we performed a comparative study on the removal of organic dye by fly ash based geopolymer (FA-G) and metakaolin based geopolymer (M-G). The mineralogical and textural analyses of samples were characterized using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM). XRD and SEM confirmed the formation of new geopolymer composites by geopolymerization reaction. The FTIR analysis showed that the adsorbents with good MB adsorption performance can be prepared from rich aluminosilicate materials. The effect of contact time, initial dye concentration, pH of solution and temperature were evaluated by batch test for purification of aqueous solution contaminated by dyestuff. The kinetic adsorption data were analyzed by pseudo-first-order, pseudo-second-order and intraparticle diffusion models. The experimental data were evaluated using the linear forms of the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich isotherm models. The best condition for maximum dye removal was found at high pH. The mechanism of kinetic adsorption by two adsorbents was described by pseudo-second-order model. Adsorption isotherms revealed that the adsorption followed a Langmuir model for adsorbents and the maximum dye adsorption capacity as predicted by Langmuir isotherm was 37.04 mg/g for FA-G and 43.48 mg/g for MK-G. On the whole, the experimental results showed that the innovative adsorbents are suitable for the effective treatment of aqueous solution contaminated with organic dye.