SNAP provides semi-automatic segmentation of structures in medical images (e.g. magnetic resonance images of the brain) using active contour methods, as well as manual delineation and image navigation. Noteworthy features are:

* Linked cursor for seamless 3D navigation
* Manual segmentation in three orthogonal planes at once
* Support for many different 3D image formats, including NIfTI
* Support for concurrent, linked viewing and segmentation of multiple images
* Limited support for color images (e.g., diffusion tensor maps)
* 3D cut-plane tool for fast post-processing of segmentation results