There are various online versions of the classic Yiddish dictionaries of the Russian-born lexicographerAlexander Harkavy.

• Harkavy's Yiddish-English (6th edition) and English-Yiddish (11th edition) Dictionary (1910): this is a digitised version of the original enhanced with index pages by Raphael Finkel.
• Yiddish-English dictionary = Yidish-Englisher verṭerbukh (1910): from the Yiddish Book Center's Digital Yiddish Library.
• Yidish-English-Hebreyisher ṿerṭerbukh = Yiddish-English-Hebrew dictionary (1925): from the Yiddish Book Center's Digital Yiddish Library.
• Yidish-English-Hebreyisher ṿerṭerbukh (1928): from the Yiddish Book Center's Digital Yiddish Library.
• Ṿerṭerbikhl fun noenṭe ṿerṭer in English un Yidish (1939): from the Yiddish Book Center's Digital Yiddish Library.