Google code scanner (Android only)

The Google code scanner API provides a complete solution for scanning code without requiring your app to request camera permission, while preserving user privacy. This is accomplished by delegating the task of scanning the code to Google Play services and returning only the scan results to your app (Video 1). All image processing occurs on the device and Google doesn't store the results or image data. The API supports the same code formats as the ML Kit Barcode Scanning API and returns the same Barcode object.

This API is ideal for apps that require seamless code scanning without the need for a custom UI or camera experience. The implementation resides entirely within Google Play services, ensuring minimal impact on the size of your app.

Starting with version 16.1.0, you can enable auto-zoom to allow the Google code scanner to automatically scan barcodes that are far away from the camera. When users point their devices at a barcode, the scanner will intelligently detect and zoom in on the barcode. This eliminates the need for manual zoom adjustments, making barcode scanning faster, more accurate and more accessible (see Video 2).

Video 1. Google code scanner integration Video 2. Auto-zoom effect

For more complex use cases that require a custom UI, we recommend using the ML Kit Barcode Scanning API directly.

If you have questions, want to submit a bug, or need assistance, check the ML Kit community page.

Before you begin

To prepare your app, complete the steps in the following sections.

Configure your app

  1. In your top-level settings.gradle file, include Google's Maven repository and Maven central repository in under the dependencyResolutionManagement block:

    dependencyResolutionManagement {
  repositories {
    google()
    mavenCentral()
  }
}

  2. Add the Google Play services dependency for the play-services-code-scanner SDK to your module's Gradle build file, which is commonly app/build.gradle:

    dependencies {
  implementation 'com.google.android.gms:play-services-code-scanner:16.1.0'
}

  3. You can configure your app to have Google Play services automatically download the scanner module to the device while your app is installed from the Play Store.

    <application ...>
  ...
  <meta-data
      android:name="com.google.mlkit.vision.DEPENDENCIES"
      android:value="barcode_ui"/>
  ...
</application>

    You can also explicitly check the scanner module availability and request download through Google Play services ModuleInstallClient API.

    If you don't enable install-time module downloads or request explicit downloads—and the scanner module isn't already installed for another use case—Google Play services downloads the scanner module the first time it's used.

Scan a code

Implement the following steps to scan a barcode.

  1. Optional: Configure the code scanner.

    If you know which barcode formats you expect to read, you can improve the speed of the barcode detector by configuring it to only detect those formats. For example, to detect only Aztec code and QR codes, build a GmsBarcodeScannerOptions object as in the following example:

    Kotlin

    val options = GmsBarcodeScannerOptions.Builder()
   .setBarcodeFormats(
       Barcode.FORMAT_QR_CODE,
       Barcode.FORMAT_AZTEC)
   .build()

    Java

    GmsBarcodeScannerOptions options = new GmsBarcodeScannerOptions.Builder()
   .setBarcodeFormats(
       Barcode.FORMAT_QR_CODE,
       Barcode.FORMAT_AZTEC)
   .build();

    By default, auto-zoom is turned off. To enable auto-zoom functionality starting in version 16.1.0, call enableAutoZoom() as shown in the following code example.

    Kotlin

    val options = GmsBarcodeScannerOptions.Builder()
   .setBarcodeFormats(...)
   .enableAutoZoom() // available on 16.1.0 and higher
   .build()

    Java

    GmsBarcodeScannerOptions options = new GmsBarcodeScannerOptions.Builder()
   .setBarcodeFormats(...)
   .enableAutoZoom() // available on 16.1.0 and higher
   .build();

  2. Get an instance of GmsBarcodeScanner, as shown in the code example:

    Kotlin

    val scanner = GmsBarcodeScanning.getClient(this)
// Or with a configured options
// val scanner = GmsBarcodeScanning.getClient(this, options)

    Java

    GmsBarcodeScanner scanner = GmsBarcodeScanning.getClient(this);
// Or with a configured options
// GmsBarcodeScanner scanner = GmsBarcodeScanning.getClient(context, options);

  3. Request a code scanning by calling startScan().

    Kotlin

    scanner.startScan()
   .addOnSuccessListener { barcode ->
       // Task completed successfully
   }
   .addOnCanceledListener {
       // Task canceled
   }
   .addOnFailureListener { e ->
       // Task failed with an exception
   }

    Java

    scanner
   .startScan()
   .addOnSuccessListener(
       barcode -> {
         // Task completed successfully
       })
   .addOnCanceledListener(
       () -> {
         // Task canceled
       })
   .addOnFailureListener(
       e -> {
         // Task failed with an exception
       });

  4. Handle the resulting Barcode.

    Kotlin

    val rawValue: String? = barcode.rawValue

    Java

    String rawValue = barcode.getRawValue();