Near infrared (NIR) spectroscopy has been widely used in agricultural product inspection because it is non-destructive, fast, and easy to operate. In this research, portable near infrared light detection instrument was used to develop a smartphone interface that could analyze the sugar content of agricultural products via the cloud system. Using the android operating system smartphone as an intermediary software to control the spectrometer configuration, spectra data are transferred and calculated in the cloud system. The user interface would then display the predicted result. So far, an intermediary software has been developed that could transfer spectra data to the cloud server, and a pre-trained guavas calibration equation was used to predict the sugar content of guava. The entire process of scanning, calculating and transferring data takes approximately 10 seconds. In the future, the functionality of the user interface could be improved by allowing manipulation of data configuration during scanning, creating a more diversified user interface with faster analysis time.