Flutter Q & A


What is the difference between a hot reload and a hot restart in Flutter?

Hot reload and hot restart are essential features in Flutter’s development toolkit, facilitating a more efficient and dynamic development process. Here’s a comprehensive explanation:


Hot Reload:

Hot reload is a powerful tool that allows developers to instantly inject new code into a running Flutter application, updating the UI and maintaining the current app state. This means you can see the changes in real-time without losing the application’s current state. It dramatically speeds up the development process by eliminating the need to restart the entire application.


For instance, if you’re tweaking the UI or fixing a bug, you can save the changes, and with a simple press of a button, the updated code is injected into the running app. This is particularly useful for experimenting with different UI layouts or testing small code modifications.


Hot Restart:

While hot reload injects code changes into the running app, hot restart goes a step further. It stops the running instance of the app and restarts it with the latest code changes. This ensures a clean slate for your application, discarding the current state. Hot restart is essential when you’ve made changes to the app’s structure or introduced modifications that require a full application restart.


For example, if you’ve added or removed dependencies, modified the app’s initialization process, or made changes that affect the entire app’s lifecycle, a hot restart is necessary.


Key Points:


  • Hot reload maintains the app’s state, allowing developers to experiment with UI changes without restarting the application.
  • Hot restart, on the other hand, restarts the entire application, ensuring that structural changes and modifications to the app’s lifecycle take effect.
  • Both features contribute to Flutter’s rapid development cycle, enhancing developer productivity.


In summary, hot reload and hot restart are integral to Flutter development, providing a seamless and efficient way to iterate on code and see changes instantly during the development process.


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Full Stack Systems Analyst with a strong focus on Flutter development. Over 5 years of expertise in Flutter, creating mobile applications with a user-centric approach.