Social networking sites form part of everyday life in classrooms at all educational levels. Within these, general social networking sites (GSNSs) offer pre-service teachers flexibility, versatility and the possibility of forming educational communities by connecting formal, non-formal and informal settings. This research analyses the nature, intensity, and type of pre-service teachers’ use of such for educational purposes in their initial training in order to detect the most important aspects for improvement. Possible factors shaping behaviour were gender, whether individuals belonged to universities operating online or in person, differences in the types of studies they were undertaking, and the time at which the questionnaire was administered, before or after the COVID-19 health crisis. To this end, we studied how much and with what aims these students use the most widely used GSNSs for educational purposes. To do so, we administered a questionnaire to a total of 812 students from 6 Spanish universities. The results show a preference for WhatsApp, YouTube, and Instagram. In addition, it was found that undergraduate students used them more intensively than postgraduate students. In the case of online universities, there was a greater need to cover affective and emotional aspects than in in-person universities. As in almost all areas, the situation caused by COVID-19 changed the way social networks were used. The findings also show that pre-service teachers consumed more information on social media than what they produced, which leads to a failure to fully exploit social capital and potential job or academic opportunities that could be generated through their own creations.