AbstractFrom the time a cell was first placed under the microscope, it became apparent that identifying two clonal cells that “look” identical is extremely challenging. Since then, cell‐to‐cell differences in shape, size, and protein content have been carefully examined, informing us of the ultimate limits that hinder two cells from occupying an identical phenotypic state. Here, we present recent experimental and computational evidence that similar limits emerge also in cellular metabolism. These limits pertain to stochastic metabolic dynamics and, thus, cell‐to‐cell metabolic variability, including the resulting adapting benefits. We review these phenomena with a focus on microbial metabolism and conclude with a brief outlook on the potential relationship between metabolic noise and adaptive evolution.This article is categorized under: Metabolic Diseases > Computational Models Metabolic Diseases > Biomedical Engineering