The rise of smartphone surveys, coupled with technological advancements, provide new ways for measuring respondents’ political attitudes. The use of open questions with requests for voice answers instead of text answers may simplify the answer process and provide nuanced information. So far, research comparing the measurement quality of text and voice answers is scarce. We therefore conducted an experiment in a smartphone survey (N = 2,402) to investigate the criterion validity of text and voice answers. Voice answers were collected using a JavaScript and PHP-based voice recording tool that resembles the voice messaging function of Instant-Messaging Services. The results show that the open questions with requests for text and voice answers differ in terms of criterion validity. More specifically, the findings indicate that voice answers result in a somewhat higher criterion validity than their text counterparts. More refined research on the measurement quality of text and voice answers is required in order to draw robust conclusions.