Wearable devices are increasingly used to evaluate psychophysiological markers of anxiety for continuous health monitoring. Consumer-grade wearable devices, such as Fitbits, have potential for widespread use and dissemination given their affordability and accessibility for both research and clinical settings. However, validation of consumer-grade devices against research-grade devices is required. This study aimed to evaluate and compare the accuracy of the Fitbit Charge 5 against a research-grade wearable device, the Equivital EQ02, in measuring psychophysiological parameters of anxiety, specifically heart rate (HR) and galvanic skin response (GSR). Fifty-five undergraduate students ( M_age = 19.4, SD_age = 1.6, 46% female) wore both Fitbit and Equivital devices whilst completing social stressor and reading tasks. Statistical analyses revealed statistically significant moderate bivariate correlations ( rs = .5–.6) and intraclass correlations (ICCs = .53–.72) for HR estimates and moderate intraclass correlations (ICCs = .46–.64) for GSR estimates across conditions ( ps < .05). Furthermore, Bland–Altman analyses revealed that the Fitbit showed a pattern of underestimation of HR (ranging from 24 –32bpm) and overestimation of GSR (ranging from –12.92 to 10.29µS) compared to the Equivital. These findings highlight potential reliability concerns with the Fitbit Charge 5 in measuring physiological data. While the device may have some utility in assessing HR and GSR, it is crucial to approach the interpretation of data from consumer-grade wearable devices with caution due to potential accuracy limitations.