Born in Hirzel in Zürich, Switzerland, he was a brother to linguist Ludwig Tobler (1827–1895).

He studied Romance philology at the universities of Zürich and Bonn, receiving his doctorate in 1857.

[1][2] The "Tobler-Mussafia law", a grammatical rule applicable to Romance languages, is named after Tobler and the Austrian philologist Adolf Mussafia.

[3] Among his better-written efforts was the five-volume Vermischte Beiträge zur französischen Grammatik ("Miscellaneous contributions to French grammar";1886–1912).

His creation of an Old French dictionary was unfinished at the time of his death, being posthumously edited and published by Erhard Lommatzsch ("Tobler-Lommatzsch", Altfranzösisches Wörterbuch; 11 volumes).