fastText is a lightweight and open-source library created by Facebook's AI Research (FAIR) team, designed for the efficient learning of word embeddings and text classification. It provides capabilities for both unsupervised word vector training and supervised text classification, making it versatile for various applications. A standout characteristic of fastText is its ability to utilize subword information, as it represents words as collections of character n-grams; this feature significantly benefits the processing of morphologically complex languages and words that are not in the training dataset. The library is engineered for high performance, allowing for rapid training on extensive datasets, and it also offers the option to compress models for use on mobile platforms. Users can access pre-trained word vectors for 157 different languages, generated from Common Crawl and Wikipedia, which are readily available for download. Additionally, fastText provides aligned word vectors for 44 languages, enhancing its utility for cross-lingual natural language processing applications, thus broadening its use in global contexts. This makes fastText a powerful tool for researchers and developers in the field of natural language processing.