Many cell functions, such as proliferation, migration and neurite outgrowth, can be quantified in simple mono-cultures without fluorescent cell labels by analyzing features of phase-contrast images. However, there are limitations to what can be achieved without cell labels, for example, extracting true cell count metrics from phase contrast images in dense cultures, and identifying different cell types and their interactions in co-culture models. Accordingly, a range of different cell-labeling strategies for IncuCyte® analysis have been developed. In this article, we review the details and pros and cons of these label- and label-free strategies and provide user guidance as to when and how these should be used.