We perform a characterization of a recently reported minibubbles (bubbles with a diameter of the order of 10‐3 m) generator in microgravity related conditions. Generation of bubbles is based on the generation of a slug flow in a capillary T‐junction, whose operation is robust to changes in the gravity level. We address questions regarding the performance under different working regimes. In particular, we focus on the regimes found within a large range of gas and liquid injection flow rates. The injection performance is characterized by measuring bubble generation frequency. We propose curves obtained empirically for the behavior of generation frequency and crossover between regimes.