Nurse practitioners’ informatics competencies are not well-understood. Limited evidence alludes to the potential need to improve the informatics competencies of nurse practitioners. The primary purpose of this study was to analyze the informatics competencies of nurse practitioners, including nurses training to become nurse practitioners, before and after completing an online learning module in nursing informatics. Six topics were covered in the investigator-developed learning module. A pre-test/post-test, one-group, quasi-experimental design was used in the study. Link to the study was emailed to members of a local nurse practitioners’ association in California and graduate nursing students at a public university in Missouri. The study was also shared on a professional networking website, LinkedIn. Data were collected from 15 nurse practitioners and two nurse practitioner students, using a demographic questionnaire and an 18-item self-assessment of informatics competency scale. A related-samples sign test was conducted to compare the pre-test and post-test scores. Statistically significant median increases (p = 0.001 to xtagstartz 0.001) were found in five areas. Findings suggest that the online learning module expanded the participants’ competencies in specific areas of informatics. The results also provide an initial understanding of nurse practitioners’ informatics competencies and inform future iterations of the study.