In recent years, studies have investigated “Subtitles as a Support” (SaS) and “Subtitling as a Task” (SaT) as two distinct approaches to audiovisual input, which have the potential to foster learners’ vocabulary. In line with the Involvement Load Hypothesis (ILH) (Laufer & Hulstijn, Applied Linguistics 22(1):1–26, 2001), Talaván (Porta Linguarum 6:41–52, 2006, p. 43) has assumed that vocabulary learning “is enhanced when subtitles are used not in a passive but in an active mode, being the students themselves the ones who create them”. This contribution addresses this assumption by means of a study in which almost 300 learners of L3-Dutch in German schools engaged with two Dutch short films, both as a more passive SaS- (sub-study 1) and a more active SaT-activity (sub-study 2). The results show that the effectiveness of SaS depends on the conditions used, with dual subtitles in L3-Dutch and L1-German yielding the highest scores. SaT also leads to significant vocabulary learning. The comparison of the sub-studies suggests that, overall, SaT is more beneficial for vocabulary acquisition than SaS, which in turn supports the ILH.