Je sais tout

Je sais tout (meaning I Know All in English) was a French magazine established by Pierre Lafitte (publisher) in 1905. It was noted for featuring the works of Maurice Leblanc, in particular the adventures of Arsène Lupin, which was first published in 1907.

Je sais tout was a popular science magazine. The magazine appeared on the 15th day of each month, but publication was interrupted from August 1914 to the end of 1914. The magazine's format was usually 17.5 cm by 24.5 cm, and contained more than 100 pages. The magazine's logo was created by Jules-Alexandre Grün. Initial circulation figures were estimated to be about 250,000. The headquarters of the magazine was in Paris.