The Brain Surface and Tractography Viewer was developed at Children’s Hospital Boston in the Fetal-Neonatal Neuroimaging and Development Science Center as part of a web front-end that automates the processing of MRI and Diffusion MRI. This application allows researchers to very rapidly explore processed MRI data in real-time within the web browser using WebGL. The application renders cortical surface reconstructions and fiber tracts generated by FreeSurfer and the Diffusion Toolkit, two automated brain imaging tools developed at the MGH Martinos Center for Biomedical Imaging. The user can view the gray-white surface and pial surface along with various curvature measures. Further, the fiber tracts are registered to the cortical surface and can be viewed inside the brain surfaces.