Doccano

Doccano is a text annotation tool for people preparing training or evaluation datasets for machine learning. Its browser interface lets teams label text together on their own machine or server.

• Text labeling: Assign document categories for sentiment analysis, mark named entities within passages, or pair source text with summaries using sequence-to-sequence tasks.
• Team projects: Multiple annotators can work in shared projects with annotation guidelines.
• Dataset exchange: Import unlabeled or already labeled datasets in multiple formats, then export completed annotations for use in other tools.
• Model-assisted annotation: Connect scripts and machine learning models through the REST API to produce labels alongside human annotation.

Doccano supports multilingual text and emoji, and its interface also works on mobile devices. It's open source under the MIT license and can run through Python or Docker, including Docker Compose. SQLite is the default database; PostgreSQL is also supported.