Infant language development is facilitated by social environments and predicted by their parents’ timely responses. However, the increasing uptake of digital technologies raises important questions about how digitally mediated interactions influence parents’ responsiveness. In the present study, the quantity (total numbers of words) and quality (unique words) of parents’ utterances to their infants were examined in contingent (less than 2 seconds) and non-contingent segments across two digital conditions (face-to-face with a tablet present vs. video chat) during a peekaboo play (N = 67, infants’ age: 18 – 26 months-old). We assessed the lexical variability using a natural language processing (NLP) approach with size-matched random sampling simulation. Preliminary results indicate (1) less lexical diversity was used in non-contingent video chat and (2) the lexical variability was similar between contingent video chat and non-contingent while playing peekaboo with a tablet. These findings suggest parents’ timely inputs play a more critical role in the video chat environment.