Abstract: Existing algorithms and a new algorithm called ‘quadratic’, for extracting stress-intensity factors (SIF) from frozen-stress photoelastic data are evaluated for application to near-tip data in three-dimensional problems. It is shown that for this class of problems, modifications to some of the existing algorithms may be necessary, in some cases, in order to ensure reliable SIF values. But that for all the algorithms, the two-parameter form of the governing equations of linear-elastic fracture mechanics (LEFM) is sufficient for use with near-tip data, even for complex three-dimensional geometries.