Tree Style Tab is a Firefox extension that displays and organizes browser tabs as a hierarchical tree structure in a sidebar.
The extension solves tab management by automatically nesting tabs opened from a current tab as children beneath it, creating a visual tree. Users can collapse branches by clicking arrows on parent tabs, reducing clutter. The tree can be manually restructured through drag and drop. This approach transforms tab organization into a visual browsing history where each branch represents a topic or search path, allowing users to maintain context and easily navigate back to originating tabs without losing their exploration trail.
Tree Style Tab suits users who open many tabs during research or deep browsing sessions and want to maintain context across related pages. It works best for workflows involving topic-based exploration where tabs naturally form hierarchical relationships. The extension is particularly valuable for users frustrated by horizontal tab bars that become unusable with many open tabs. It is available as a signed package through Mozilla Add-ons for supported Firefox versions, with legacy packages available for older Firefox versions through alternative archives.
The project maintains active continuous integration with builds generated for each commit. Development builds are available through the CI/CD action artifacts, though they require manual extraction and atypical loading methods since they are unsigned. The extension is written in JavaScript and uses the WebExtensions API, making it compatible with Firefox's modern extension architecture.
