RNAhybrid is a flexible online tool for predicting microRNA (miRNA) targets, offering a unique and user-friendly interface. Recent updates include the ability to disallow G:U base pairs in the seed region and a seed-match speed-up, which reduces computation time by 8 times. The program can now also be accessed as a web service, allowing remote calls from user-implemented programs. RNAhybrid's flexibility is demonstrated through the prediction of a non-canonical target site for *Caenorhabditis elegans* miR-241 in the 3′-untranslated region of *lin-39*. The tool is available at http://bibiserv.techfak.uni-bielefeld.de/rnahybrid. The article highlights the importance of miRNA target prediction in understanding the miRNA regulatory network and provides a detailed overview of RNAhybrid's algorithmic core, features, and usage.RNAhybrid is a flexible online tool for predicting microRNA (miRNA) targets, offering a unique and user-friendly interface. Recent updates include the ability to disallow G:U base pairs in the seed region and a seed-match speed-up, which reduces computation time by 8 times. The program can now also be accessed as a web service, allowing remote calls from user-implemented programs. RNAhybrid's flexibility is demonstrated through the prediction of a non-canonical target site for *Caenorhabditis elegans* miR-241 in the 3′-untranslated region of *lin-39*. The tool is available at http://bibiserv.techfak.uni-bielefeld.de/rnahybrid. The article highlights the importance of miRNA target prediction in understanding the miRNA regulatory network and provides a detailed overview of RNAhybrid's algorithmic core, features, and usage.