FairBase (Fungal A-to-I RNA editing dataBase) is the first comprehensive fungal A-to-I RNA editing database. It includes a comprehensive collection of A-to-I editing sites identified in six filamentous fungi, together with extensive annotations for each editing site. In FairBase, users can conveniently search editing sites and obtain editing levels for each editing site in various RNA-seq samples. To better understand fungal RNA editing, genome browsers and pathways both are built in FairBase, which allow users to explore RNA editing sites in genomic and pathway context, respectively.