People are increasingly using video calls for high-stakes interactions that once required face-to-face contact: from medical consultations1,2, to job interviews3, to court proceedings4. But video calling introduces a new communication issue: minor glitches, or intermittent errors in the transmission of audiovisual information during a virtual interaction5. Here, through five experiments and three supplementary studies using both live and recorded interactions, we show that minor audiovisual glitches during video calls harm interpersonal judgements in consequential life domains (for example, hiring decisions after a virtual interview, or trust in a medical provider after a telehealth visit). In addition, two archival datasets from real-world video calls reveal that glitches are associated with both reduced social connection and a lower likelihood of being granted criminal parole. We find that audiovisual glitches damage interpersonal judgements because they break the illusion of face-to-face contact (for example, by distorting faces, misaligning audio and visual cues or making movements appear ‘choppy’), evoking ‘uncanniness’—a strange, creepy or eerie feeling6,7. As the uncanniness of a glitch increases, so does its negative effect on interpersonal judgements. Furthermore, audiovisual glitches undermine interpersonal judgements only in video calls that simulate face-to-face interaction, showing that the negative effect produced by glitches goes beyond mere disruptiveness, comprehension difficulties and negative attributions. These findings have important implications for digital equity. Despite being considered a boon to access, virtual communication might unintentionally perpetuate inequality. Because disadvantaged groups often have poorer internet connections8,9,10,11,12, they are likely to encounter more glitches, and, in turn, to experience worse outcomes in consequential contexts such as health, careers, justice and social connection.