The most famous rule on the speed of subtitles is the six-second rule. This study investigates if the six-second rule is too slow for contemporary viewers. It also addresses the question of whether subtitle processing depends on the speech rate of film dialogues and on viewer’s proficiency in the language of the film soundtrack. With these questions in mind, the study tested 53 Polish viewers watching English videos at two different speech rates (slow and fast), subtitled into Polish in accordance with the six-second rule. It examined participants’ reading patterns and comprehension and asked them to assess subtitle speed and the congruity of subtitles with the dialogue. Analysing people’s eye movements enabled to measure that viewers were looking at subtitles for only about 30% of the subtitle display time. The study found that the film speech rate affected comprehension: faster dialogues, implying more text condensation in subtitles, resulted in lower comprehension compared to slow speech rates. Viewers more proficient in the language of the film soundtrack spent less time gazing at subtitles than those who had only elementary knowledge of the language.