AbstractMotivationThe visualization of biological data is a fundamental technique that enables researchers to understand and explain biology. Some of these visualizations have become iconic, for instance: tree views for taxonomy, cartoon rendering of 3D protein structures or tracks to represent features in a gene or protein, for instance in a genome browser. Nightingale provides visualizations in the context of proteins and protein features.ResultsNightingale is a library of re-usable data visualization web components that are currently used by UniProt and InterPro, among other projects. The components can be used to display protein sequence features, variants, interaction data, 3D structure, etc. These components are flexible, allowing users to easily view multiple data sources within the same context, as well as compose these components to create a customized view.Availability and implementationNightingale examples and documentation are freely available athttps://ebi-webcomponents.github.io/nightingale/. It is distributed under the MIT license, and its source code can be found athttps://github.com/ebi-webcomponents/nightingale.