Our aim was to evaluate the psychometric properties of the online administered format of the Test of Narrative Language-Second Edition (TNL-2; Gillam & Pearson, 2017), given the importance of assessing children's narrative ability and considerable absence of psychometric studies of spoken language assessments administered online. The TNL-2 was administered to 357 school-age children at risk for language and literacy difficulties as part of a randomized controlled trial, across three annual cohorts, at three time points (pretest, posttest, and 5-month follow-up). Cohort 3 students were tested using an online format at posttest and at follow-up. We compared the Cronbach's alpha internal consistency reliability of the TNL-2 online testing scores with in-person scores from TNL-2 normative data and Cohort 3 in-person testing at pretest, and interrater reliability for Cohort 3 across test points. In addition, we examined measurement invariance across test occasions and the criterion validity of the TNL-2, the latter based on its correlations with narrative sample measures (Mean Length of Utterance in words and the Monitoring Indicators of Scholarly Language rubric). Internal consistency reliability, interrater reliability, and measurement invariance analyses of the online and in-person administration of the TNL-2 yielded similar outcomes. The criterion validity of the TNL-2 was found to be good. TNL-2 psychometric properties from online administration were generally in the good range and were not significantly different from in-person testing. When administered online using standardized procedures, the TNL-2 is valid and reliable for use in assessing narrative language proficiency in school-age children at risk for language and learning difficulties.