Recent developments in test methodologies for nanoindenter-based small-length-scale mechanical characterization are overviewed, such as micropillar compression, cantilever beam bending, and tensile tests. Emphasis is placed on the possibilities offered by in situ testing in transmission and scanning electron microscopes, as well as examining strain rate and temperature dependence of mechanical strength. The versatility and growing impact of new nanomechanical characterization tools is highlighted through selected recent examples, such as indentation (sample) size effect, crack-tip plasticity, radiation damage, indentation creep, laser additive manufacturing, and crystalline/amorphous high-entropy alloys. Graphical abstract: (Figure presented.)