Foods with a low glycemic index are a good choice for diabetics, including flakes created from mangrove fruit flour (pedada and lindur), porang as well as mocaf flour. These products contain dietary fiber and bioactive compounds and are thus suitable for lowglycemic functional foods. Therefore, this study aims to determine the glycemic index of various flour mixtures' flakes products, using a one-factor completely randomized design. Therefore, ten formulations were created with mangrove fruit flour: porang or mocaf flour ratio of (0:100, 10:90, and 20:80). The yields were then analyzed for proximate and organoleptic characteristics, while the glycemic index was measured in vivo with 22 subjects. Subsequently, blood samples were collected from the fingers of the subjects, followed by the assessment and comparison of blood glucose with a pure glucose curve to obtain the glycemic index. Furthermore, the glycemic load was calculated by multiplying the value derived with available carbohydrates. This study showed that the flakes produced from the combination of PFF and LFF with mocaf flour indicated lower GI values compared to the control (100% mocaf flour), namely at 40.96-48.27 with GL 9.83-11.96. The best treatments were obtained in flake product P20R80, characterized by the lowest glycemic index and glycemic load of 34.42 and 8.36, respectively. Meanwhile, the highest values were obtained in MFF0M100, at 51.02 and 12.72, correspondingly. The results indicate the inclusion of these flake products in the low glycemic index category.