WebAnno is a general purpose web-based annotation tool for a wide range of linguistic annotations. WebAnno offers annotation project management, freely configurable tagsets and the management of users in different roles. WebAnno uses technology from the brat rapid annotation tool for visualizing and editing annotations in a web browser. It supports annotation and visualization of arbitrarily large documents, pluggable import/export filters, the curation of annotations across various users, and farming out annotations to a crowdsourcing platform.

Currently, WebAnno allows POS, Named Entity, Dependency Parsing and co-reference resolution annotations. The architecture design allows to add additional modes of visualization and editing, when new kinds of annotations are to be supported.

The added value of WebAnno, as compared to previous annotation tools, is on the one hand constituted by its web-based interface to skilled as well as unskilled annotators, which unlocks a potentially very large workforce. On the other hand, the tool's support functionality for quality control and annotator management and curation lowers the entrance barrier for new annotation projects.

We created WebAnno to fulfill the following requirements:

  • Flexibility: Support of several annotation layers, several import and export formats, and extendibility to other frontends.
  • Web-based: Increased availability, distributed work, no installation effort.
  • Open Source: Usability of our tool in future projects without restrictions, under the Apache 2.0 license.
  • Quality and User Management: Integrated different user roles (administrator, annotator, and curator) support for several users, inter-annotator agreement measurement, data curation, and progress monitoring.
  • Interface to Crowdsourcing: unlocking a very large distributed workforce.
  • Pre-annotated and un-annotated documents: supporting new annotations, as well as manual corrections of automatic annotations.


The source code is provided under the Apache Software License (ASL) version 2.


Additional Attributes


A Web-based Tool for the Integrated Annotation of Semantic and Syntactic Structures

Richard Eckart de Castilho, Éva Mújdricza-Maydt, Seid Muhie Yimam, Silvana Hartmann, Iryna Gurevych, Anette Frank, Chris Biemann
In: Proceedings of the workshop on Language Technology Resources and Tools for Digital Humanities (LT4DH) at COLING 2016, p. 76--84, December 2016
[Online-Edition: https://webanno.github.io/webanno/]

Automatic Annotation Suggestions and Custom Annotation Layers in WebAnno

Seid Muhie Yimam, Richard Eckart de Castilho, Iryna Gurevych, Chris Biemann
In: Proceedings of the 52nd Annual Meeting of the Association for Computational Linguistics. System Demonstrations, p. 91--96, June 2014
Association for Computational Linguistics
[Online-Edition: https://webanno.github.io/webanno/]

WebAnno: a flexible, web-based annotation tool for CLARIN

Richard Eckart de Castilho, Chris Biemann, Iryna Gurevych, Seid Muhie Yimam
In: Proceedings of the CLARIN Annual Conference (CAC) 2014, p. online, 2014
[Online-Edition: https://webanno.github.io/webanno/]

WebAnno: A Flexible,Web-based and Visually Supported System for Distributed Annotations

Seid Muhie Yimam, Iryna Gurevych, Richard Eckart de Castilho, Chris Biemann
In: Proceedings of the 51st Annual Meeting of the Association for Computational Linguistics (System Demonstrations) (ACL 2013), p. 1-6, August 2013
Association for Computational Linguistics
[Online-Edition: https://webanno.github.io/webanno/]
A A A | Drucken Print | Impressum Impressum | Sitemap Sitemap | Suche Search | Kontakt Contact | Webseitenanalyse: Mehr Informationen
zum Seitenanfangzum Seitenanfang