Фактически, я изучил все содержание.

English Translation

In fact, I studied all the contents.

Pronunciation: все́ → всё

This is one of those cases where whatever person or software is writing the pronunciation needs to know that содержание is singular neuter and thus все must be, too. This means that it’s actually всё rather than все (the plural form), even though when the two dots are omitted (as they sometimes are), the words look the same.