Obtain Screenshot from Android Devices

Capture screenshots from Android devices using ADB commands.

Prerequisites

• ADB (Android Debug Bridge) must be installed and available in PATH. On Mac, you may try to find ADB tool in ~/Library/Android/sdk/platform-tools/.
• Device must be connected via USB with USB debugging enabled, or connected via Wi-Fi debugging
• Device must be authorized (adb authorization dialog accepted on device)
• Emulator could be used as a device.

Quick Start

First of all, querying whether there are connected devices.

# List connected devices
adb devices -l

• If there is no device connected, stop and asks the user to connect device or launch the emulator.
• If there is only one connected device, you don't need to add <device_serial> in the following commands. Otherwise, you will have to add the device serial to choose which device to use.

Capture a screenshot and pull it to local machine:

adb exec-out screencap -p > ./screenshot.png

The screenshot will be saved in PNG format as ./screenshot.png.

Common Workflows

Capture Screenshot from Specific Device

When multiple devices are connected, specify the device serial:

# Capture from specific device
adb -s <device_serial> exec-out screencap -p > ./screenshot.png

Capture Screenshot with Timestamp

# Generate filename with timestamp
filename="screenshot_$(date +%Y%m%d_%H%M%S).png"
adb -s <device_serial> exec-out screencap -p > ./$filename

Troubleshooting

Device not found

• Ensure USB debugging is enabled on the device (Settings > Developer options > USB debugging)
• Check cable connection
• Run adb devices to verify device is detected
• Accept the RSA fingerprint dialog on the device if shown

Permission denied

• Ensure the device has authorized the computer (check for authorization dialog on device)
• Try restarting ADB server: adb kill-server && adb start-server

Screenshot is black or empty

• Ensure the device screen is on and unlocked
• Some secure screens (banking apps, etc.) cannot be captured

Use Case Example: Preview Jetpack Compose Component

If you have an Jetpack Compose preview component, you can use PreviewActivity to launch the preview.

$ ./gradlew installDebug
$ adb shell am start -n <package>/androidx.compose.ui.tooling.PreviewActivity -a android.intent.action.MAIN -c android.intent.category.LAUNCHER --es composable <preview-component-package-name> --splashscreen-show-icon
$ adb exec-out screencap -p > ./compose_preview.png

If the package name is com.example.app and the preview component name is com.example.app.MainActivityKt.MainScreenPreview, the command to use will be

$ ./gradlew installDebug
$ adb shell am start -n com.example.app/androidx.compose.ui.tooling.PreviewActivity -a android.intent.action.MAIN -c android.intent.category.LAUNCHER --es composable com.example.app.MainActivityKt.MainScreenPreview --splashscreen-show-icon
$ adb exec-out screencap -p > ./compose_preview.png

The UI output of the preview will be stored in ./compose_preview.

Clean up

Finally, after the execution, remember to delete all screenshots unless the users explictly ask to keep them.