Slip gradients near the tips of earthquake ruptures and faults are typically linear. For non-interacting faults or earthquake ruptures, tip tapers are scale invariant, and about 1--2 orders of magnitude larger for faults than for earthquakes. For fault tips interacting with other faults, the taper can be as much as a factor of 10 greater than for non-interacting faults. For earthquake ruptures, taper is also greater by as much as a factor of 10 for tips of rupture segments in the interior of the main rupture, tips in which the earthquake has propagated to the end of the fault, and tips which interact with the stress-drop of a previous earthquake on the same fault. Tip taper for faults increases with the strength of the wall rock. These observations are consistent with fracture mechanics models in which inelastic deformation occurs in a volume surrounding the crack tip.