Je sais tout (meaning I Know All in English) was a French magazine established by in 1905. It was noted for featuring the works of Maurice Leblanc, in particular the adventures of Arsène Lupin, which was first published in 1905. Je sais tout was published in its original form until 15 January 1922, when it was reformed as Je sais tout, la revue de la découverte (meaning I Know All, Review of Discovery in English), and was published on the 1st of the month instead. The last issue of the new format, and thus Je sais tout overall, was released on 1 September 1939.