Does Android app need back button?

Question

Do I always have to put "back" button in the top left corner of the app?

Following the quote:

Sometimes the back button is on the left, sometimes it’s not. They may be physical buttons, capacitive buttons, on-screen buttons, or some combination of two or three. Even the graphics for back, home, and running apps vary between devices made by different OEMs.

I suppose I always have to put back button as there might not be one on the device but it's a bit old article and now usually all Android devices have bottom navigation bar with a back button. But does it eliminate the need of the actual "back" button in the app?

Answer 1

Unlike iOS, Android actually allows two different kinds of navigation: hierarchical (based on screen hierarchy) and temporal (based on the order in which screens were visited). It's just like in a browser: you have navigation within a web page and then the browser navigation which takes you back in the order you visited.

The arrow that's generally found in the app bar is actually an "Up" button, as it goes up in hierarchy. More on this in Google's Material Design HIG.

As for whether you need to use the up button: While you can rely on the "back" button being there, you can't rely on it navigating back in your app hierarchy. A different app might have launched your Android app and back would then navigate back to that app. Or a notification might have launched a specific nested screen within your app.

Whatever the case, it's important to include a way to navigate within your app on all your app screens, just like you would include navigation on all your website pages without relying on the browser's back button.

Answer 2

Considering there are thousands of android phones, you can conclude that some have capacities buttons, some on-screen, etc. It's a variable you cannot control.

Since you can only control what's happening within your app's boundary, I would suggest providing the best UX (allowing users to go back to where they came from). Meaning, provide the back button.

Without knowing how your app is designed and structured, consider that some simple / flat architecture apps don't require the back button simply because there is no need. Users might be able to travel from screen to screen simply using a menu.

But if your app architecture is deep, you will need a back option or some other gesture based approach to go back.

There is no definite yes or no answer, it all depends.

Answer 3

I find it is best to include the UI back button by default (for the reasons listed by @Tin Man as well as parity and operational efficiency when designing an app for both iOS & Android). However, you should consider the implications of doing so on a screen-by-screen basis.

Additionally, you may want to specify different actions for the hardware back button — for instance, you may want it to exit the app to the home screen rather than allow the user to navigate back/up in your app when, eg. submitting a request to the server.

Answer 4

Adding a back button may help, both from the aesthetic perspectives and the design as well. However, it is not necessary to keep the back button on the home screen of the app which might have led to the closing of the application you could keep an exit button. Otherwise, we can leave that to the hardware buttons or using the home button to clear the running app.