Hybrid media context and the infodemic have increased the threat of disinformation, particularly among young people who mostly consume digital content. This article aims to identify the competencies needed to detect low-quality content linked to disinformation by Journalism and Communications undergraduates from Argentina, Chile, and Spain. Based on a double comparative study by countries and levels of education, it tries to predict the skills of future journalists in recognising false information. From an online questionnaire, the participants (N=300) evaluated the quality observed (minimum, average or excellent) and the problems detected from 12 items published in both conventional and pseudo-media. The comparison of results with the expert group shows that about 60% of the students have difficulties in identifying quality accurately and that this ability is higher in the advanced groups. From a selection of five news items, the participants were only able to successfully report 25.3% of the real mistakes in the texts. The correct identification of these mistakes improves in news related to the COVID-19 pandemic. Conclusions reveal that undergraduates overestimate their ability to detect disinformation, with a self-perception of 3.46 out of 5. The results also indicate that their media diet combines digital media and social media as a priority, while traditional media have a residual nature.