AfroLID: A Neural Language Identification Tool for African Languages

Language identification (LID) is a crucial precursor for NLP, especially for mining web data. Problematically, most of the world's $7000$+ languages today are not covered by LID technologies. We address this pressing issue for Africa by introducing~\ourLID, a neural LID toolkit for $517$ African languages and varieties.~\ourLID~exploits a multi-domain web dataset manually curated from across $14$ language families utilizing five orthographic systems. When evaluated on our blind Test set,~\ourLID~achieves $95.89$ $F_1$-score. We also compare~\ourLID~to five existing LID tools that each cover a small number of African languages, finding it to outperform them on most languages. We further show the utility of~\ourLID~in the wild by testing it on the acutely under-served Twitter domain. Finally, we offer a number of controlled case studies and perform a linguistically-motivated error analysis that allow us to both showcase~\ourLID's powerful capabilities and limitations.