No reference documentation in Android Studio

In Android Studio 4.1.1, I solved the problem by installing the Android SDK platform for my compile build version. In my case, that was Android 10.0 (API Level 29).

  1. Open File > Settings to open the Settings window.
  2. Go to Appearance & Behavior > System Settings > Android SDK.
  3. Select your target build in the SDK Platforms tab (for example, Android 10.0).
  4. Click OK to install the SDK platform.

Once it is done installing, check whether the documentation popups are back.

P.S. The target build is the compileSdkVersion setting in the build.gradle file.

Note: as of AS 3.6.2 (or, maybe, even earlier) this is irrelevant and does not answer the question.

Answer for older Android Studio versions:

You Must Download Documentation for Android SDK from SDK Manager


So for me the solution in Android Studio 4.1.1 was that I forgot to download the sources for SDK 30.

  1. Go to Tools > SDK Manager
  2. Check Show Package Details
  3. See if Sources for Android 30 is checked