What’s new in Dash 3.0

Dash 3.0 introduces major updates that improve performance, developer experience, and extensibility across the board. One of the most visible changes is the refreshed DevTools UI. Developers now get improved visual tools like the callback graph, version notifications, and more visibility into Dash internals to streamline debugging and iteration.

Under the hood, Dash 3.0 modernizes its framework by updating to a newer version of React. This upgrade benefits component developers by making it easier to use modern React tooling and stay aligned with broader web development trends. The update also includes a performance boost for Dash apps with many components or callbacks. Layouts now avoid unnecessary rerendering, leading to a noticeable improvement in responsiveness.

A standout feature in Dash 3.0 is Dash Hooks. This new capability lets developers control different parts of the Dash app lifecycle using Python modules. Hooks include setup, layout, routing, callback, error, and index hooks. These can be used to inject UI elements, scripts, stylesheets, or shared functionality without editing app layout code.

Examples shown in the demo include:

• A layout hook that adds a customizable header without touching the layout itself
• A beautify layout hook that automatically reorganizes charts and applies styling using Dash Design Kit
• The ability to turn these hooks into shareable Python packages for reuse within teams or across projects

Other use cases discussed include injecting data sources into callbacks, integrating AI chat interfaces, managing templates, and reusing layout logic with minimal overhead.

Dash Hooks significantly increase reusability and simplify modular app development in Python. The Dash documentation team has published guides and examples to help users get started with building their own hook modules.

Watch the video to see the live demos and learn how to start using Dash Hooks in your own projects.