doccano

doccano is an open-source text annotation tool for humans. It helps machine learning practitioners create labeled data for text classification, sequence labeling, and sequence to sequence tasks, including sentiment analysis, named entity recognition, and text summarization.

You create a project, upload data, and start annotating. It includes collaborative annotation, multi-language support, mobile support, emoji support, a dark theme, and a RESTful API.

doccano can be self-hosted with pip, Docker, or Docker Compose, so teams keep their data on their own infrastructure. A public demo is available for trying the labeling interface before installing.