What are hot reload and hot restart in Flutter?

Hot reload and hot restart are two essential features of the Flutter framework that make the development process more efficient and productive. Let’s explore these concepts in more detail:

Hot Reload:

Hot reload allows you to make changes to your code and instantly see the results without losing the current state of your app. When you save your changes, the Flutter framework injects the updated code into the running Dart Virtual Machine (VM), replacing the old code. The UI is then rebuilt, reflecting the changes you made.

• This feature is particularly beneficial during UI development, as it eliminates the need to restart the entire app and navigate back to the specific screen you were working on.
• Hot reload is fast and seamless, allowing you to experiment and iterate quickly. It significantly shortens the feedback loop and speeds up the development process.
• It is worth mentioning that hot reload only updates the code that has changed, so you don’t have to wait for the entire app to rebuild.

Hot Restart:

Hot restart, on the other hand, completely restarts the app, discarding the current UI state. When you perform a hot restart, the Dart VM is initialized again, and the app is launched from scratch.

• This feature is useful when you have made changes that require a fresh start, such as modifying the app’s navigation flow or changing the app’s dependencies.
• However, it is essential to keep in mind that a hot restart will lose the current app state, so any unsaved data or user input will be lost.
• Compared to a cold restart, which involves manually stopping and rebuilding the app from scratch, hot restart provides a faster way to test your changes while keeping your app in the development state.

Both hot reload and hot restart are valuable tools in a Flutter developer’s arsenal. They improve productivity, reduce development time, and help in quickly iterating and refining the app’s UI and functionality.