Research has shown that novel words can be learned through the mechanism of statistical or cross-situational word learning (CSWL). So far, CSWL studies using adult populations have focused on the presentation of spoken words. However, words can also be learned through their written form. This study compared auditory and orthographic presentations of novel words with different degrees of phonological overlap using CSWL in a laboratory-based and an online-based approach. In our analyses, we first compared accuracy across modalities, with our findings showing more accurate recognition performance for CSWL when novel words were presented through their written forms (orthographic condition) rather than through their spoken forms (auditory condition). Bayesian modeling suggested that accuracy for the orthographic condition was higher in the laboratory compared to online, whereas performance in the auditory condition was similar across both experiments. We discuss the implications of our findings for presentation modality and the benefits of our online testing protocol for future research.