Recogito is a collaborative platform for adding annotations and semantic data to text files and images. In the Tutorial section, users will find a ten-minute introduction that briefly illustrates how to add and annotate a single document. Annotations can indicate that a selected snippet of text or region on an image refers to either a place, a person, or an event. When tagging locations, automatic suggestions are provided from a number of built-in gazetteers. The semantic annotations are useful for exploring the relationships across a set of documents (e.g., by finding all mentions of a specific person). Users can also publicly publish their annotated documents by marking them "visible to all." The free instance of Recogito on Pelagios.org imposes a 200MB total size limit for data stored within a workspace. However, images may be stored on an IIIF server outside of Recogito's limit. Recogito is free software, distributed under the Apache license, with source code available on GitHub. The project README also includes instructions for running a Recogito instance on one's own server.