redux-devtools

Redux DevTools is a set of debugging tools built for Redux, a popular way of managing application state in JavaScript web apps. "State" here means all the data your app keeps track of, like which user is logged in, what items are in a shopping cart, or which tab is currently selected. Redux DevTools lets developers inspect and interact with that state in real time while building or troubleshooting an app.

The main feature is the ability to see every action your app performs and the resulting change in state, laid out step by step in a visual panel. A developer can step backward through those actions, a feature called "time travel debugging," to reproduce a bug exactly as it happened or to verify that a specific user action produced the correct outcome. There is also hot reloading, which means the app can be updated while running without losing the current state, and action replay, which lets you re-run a recorded sequence of user interactions.

The tools come in three forms. The most common is a browser extension for Chrome, Edge, and Firefox that adds an inspector panel directly inside the browser's built-in developer tools. There is also a standalone desktop app for cases where a browser extension is not convenient, and a version that can be embedded directly inside a React app as a component. Redux is a specific tool, but the README notes that Redux DevTools can also integrate with other state-management approaches that follow a similar pattern.

The project is organized as a collection of related packages in a single repository, which is a common structure for tools with many interconnected parts. It is written in TypeScript, a variant of JavaScript that adds type annotations to help catch errors before code runs.