Pressurized metered dose inhalers are recommended to be used in combination with spacers, yet inhaler technique and adherence are poor. A novel digital "smart" spacer can record spacer use and technique errors and could facilitate personalized education. In this proof-of-concept study, we assessed the usability of the digital spacer and explored its effects on inhaler technique, adherence, long-term systemic drug exposure and clinical outcomes in COPD. Usability was deemed high. One month after personalized digital spacer inhaler education, the mean number of errors per patient per day decreased with 36%, from 6.40 errors/day to 4.07 errors/day (p = 0.038). Drug exposure was confirmed by bioanalytical scalp hair analysis of formoterol. No significant change in clinical outcomes was observed. This study demonstrates the digital spacer's potential value in inhaler education, but larger, longer-term studies are required.