The European Plate Observing System (EPOS) is a large and complex European e-infrastructure that facilitates the integrated use of multi-disciplinary datasets and services for Solid Earth research. EPOS’ GNSS (Global Navigation Satellite Systems) component provides access to GNSS data and products. This paper introduces a new EPOS web portal ( https://gnssquality-epos.oma.be ) that has been developed with the aim to provide the necessary information to monitor the availability and quality of daily GNSS data that are discoverable through EPOS. Currently, the web portal includes the tracking performances of more than 1600 GNSS stations. Several GNSS data quality indicators (DQIs), such as the number of observed versus expected observations, the number of missing epochs, the number of observed satellites, the maximum number of observations, the number of cycle slips, the Standard Point Positioning results, and the multipath values on code observation are monitored and their plots are available online. These DQIs provide helpful information that can be used to detect a potential degradation of the quality of the GNSS observations. Here, we will present the status of the web portal, the considered data quality indicators, and their benefits for GNSS data users.