Open educational resources (OER) have been identified as having the potential to extend opportunities for learning to non-formal learners. However, little research has been conducted into the impact of OER on non-formal learners. This paper presents the results of a systematic survey of more than 3,000 users of open educational resources (OER). Data was collected between 2013 and 2014 on the demographics, attitudes and behaviours of users of three repositories. Questions included a particular focus on the behaviours of non-formal learners and the relationship between formal and non-formal study. Frequency analysis shows that there are marked differences in patterns of use, user profiles, attitudes towards OER, types of materials used and popularity of different subjects. The experience of using OER is fairly consistent across platforms in terms of satisfaction and impact on future behaviour. On the whole, non-formal learners surveyed were highly positive about their use of OER and believe they will continue to use them. With regards to this making formal study more likely some degree of polarization was observed: some believed formal study was now more likely, while others felt it made this less likely. On the whole, while non-formal learners are enthusiastic about using free and online resources, the language and concept of OER does not seem to be well understood in the groups surveyed. A range of findings relating to OER selection and use as well as differences between repositories are explored in the discussion.