Empirical evidence remains sparse about how videos enhanced with first-language (L1) and second-language (L2) subtitles influence cognitive load in L2 learners. To address this point, 25 Korean undergraduate students were exposed to six short videos: baseline, L1-subtitled, and L2-subtitled videos at both high and low difficulty levels (determined by linguistic complexity and speech rate). Baseline videos included subtitles in Arabic, a language unfamiliar to the participants. As participants viewed the videos, their brains' electrical activity was recorded using electroencephalography (EEG). After each video, participants completed a self-report questionnaire based on the video they had just watched. Analyses of the EEG data and questionnaire responses consistently suggested that, compared to baseline videos, L1-subtitled videos reduce cognitive load in L2 learners. However, findings for L2-subtitled videos were less consistent. While the EEG results indicated no significant difference in cognitive load between L2-subtitled and baseline videos, participants reported significantly higher cognitive effort for baseline videos than for L2-subtitled videos. Notably, these results did not vary according to the difficulty levels of the videos.