How can I detect when an Android application is running in the emulator?

How about this solution (class implementation of SystemProperties is available here):

private var sIsProbablyRunningOnEmulator: Boolean? = nullfun isProbablyRunningOnEmulator(): Boolean {    var result = sIsProbablyRunningOnEmulator    if (result != null)        return result    // Android SDK emulator    result = (Build.FINGERPRINT.startsWith("google/sdk_gphone_")            && Build.FINGERPRINT.endsWith(":user/release-keys")            && Build.MANUFACTURER == "Google" && Build.PRODUCT.startsWith("sdk_gphone_") && Build.BRAND == "google"            && Build.MODEL.startsWith("sdk_gphone_"))            //            || Build.FINGERPRINT.startsWith("generic")            || Build.FINGERPRINT.startsWith("unknown")            || Build.MODEL.contains("google_sdk")            || Build.MODEL.contains("Emulator")            || Build.MODEL.contains("Android SDK built for x86")            //bluestacks            || "QC_Reference_Phone" == Build.BOARD && !"Xiaomi".equals(Build.MANUFACTURER, ignoreCase = true) //bluestacks            || Build.MANUFACTURER.contains("Genymotion")            || Build.HOST=="Build2" //MSI App Player            || Build.BRAND.startsWith("generic") && Build.DEVICE.startsWith("generic")            || Build.PRODUCT == "google_sdk"            // another Android SDK emulator check            || SystemProperties.getProp("ro.kernel.qemu") == "1"    sIsProbablyRunningOnEmulator = result    return result}

Note that some emulators fake exact specs of real devices, so it might be impossible to detect it. I've added what I could, but I don't think there is a 100% way to detect if it's really an emulator or not.

Here a tiny snippet you can make in the APK to show various things about it, so you could add your own rules:

        textView.text = "FINGERPRINT:${Build.FINGERPRINT}\n" +                "MODEL:${Build.MODEL}\n" +                "MANUFACTURER:${Build.MANUFACTURER}\n" +                "BRAND:${Build.BRAND}\n" +                "DEVICE:${Build.DEVICE}\n" +                "BOARD:${Build.BOARD}\n" +                "HOST:${Build.HOST}\n" +                "PRODUCT:${Build.PRODUCT}\n"

One common one sems to be Build.FINGERPRINT.contains("generic")

Well Android id does not work for me, I'm currently using:

"google_sdk".equals( Build.PRODUCT );