Interstitial ads

Interstitial ads are full-screen ads that cover the interface of an app until closed by the user. They're typically displayed at natural transition points in the flow of an app, such as between activities or during the pause between levels in a game. When an app shows an interstitial ad, the user has the choice to either tap on the ad and continue to its destination or close it and return to the app. Case study.

This guide shows you how to integrate interstitial ads into an iOS app.

Prerequisites

Always test with test ads

When building and testing your apps, make sure you use test ads rather than live, production ads. Failure to do so can lead to suspension of your account.

The easiest way to load test ads is to use our dedicated test ad unit ID for iOS interstitials:
ca-app-pub-3940256099942544/4411468910

It's been specially configured to return test ads for every request, and you're free to use it in your own apps while coding, testing, and debugging. Just make sure you replace it with your own ad unit ID before publishing your app.

For more information about how the Mobile Ads SDK's test ads work, see Test Ads.

Implementation

The main steps to integrate interstitial ads are:

  1. Load an ad.
  2. Register for callbacks.
  3. Display the ad.

Load an ad

Loading an ad is accomplished using the load(adUnitID:request) method on the GADInterstitialAd class.

Swift

import GoogleMobileAds
import UIKit

class ViewController: UIViewController {

  private var interstitial: GADInterstitialAd?

  override func viewDidLoad() {
    super.viewDidLoad()

    Task {
      do {
        interstitial = try await GADInterstitialAd.load(
          withAdUnitID: "ca-app-pub-3940256099942544/4411468910", request: GADRequest())
      } catch {
        print("Failed to load interstitial ad with error: \(error.localizedDescription)")
      }
    }
  }
}

SwiftUI

import GoogleMobileAds

class InterstitialViewModel: NSObject, GADFullScreenContentDelegate {
  private var interstitialAd: GADInterstitialAd?

  func loadAd() async {
    do {
      interstitialAd = try await GADInterstitialAd.load(
        withAdUnitID: "ca-app-pub-3940256099942544/4411468910", request: GADRequest())
      interstitialAd?.fullScreenContentDelegate = self
    } catch {
      print("Failed to load interstitial ad with error: \(error.localizedDescription)")
    }
  }
InterstitialViewModel.swift

Objective-C

@import GoogleMobileAds;
@import UIKit;

@interface ViewController ()

@property(nonatomic, strong) GADInterstitialAd *interstitial;

@end

@implementation ViewController

- (void)viewDidLoad {
  [super viewDidLoad];
  GADRequest *request = [GADRequest request];
  [GADInterstitialAd loadWithAdUnitID:@"ca-app-pub-3940256099942544/4411468910"
      request:request
      completionHandler:^(GADInterstitialAd *ad, NSError *error) {
    if (error) {
      NSLog(@"Failed to load interstitial ad with error: %@", [error localizedDescription]);
      return;
    }
    self.interstitial = ad;
  }];
}

Register for callbacks

In order to receive notifications for presentation events, you must implement the GADFullScreenContentDelegate protocol and assign it to the fullScreenContentDelegate property of the returned ad. The GADFullScreenContentDelegate protocol handles callbacks for when the ad presents successfully or unsuccessfully, and when it is dismissed. The following code shows how to implement the protocol and assign it to the ad:

Swift

import GoogleMobileAds
import UIKit

class ViewController: UIViewController, GADFullScreenContentDelegate {

  private var interstitial: GADInterstitialAd?

  override func viewDidLoad() {
    super.viewDidLoad()

    Task {
      do {
        interstitial = try await GADInterstitialAd.load(
          withAdUnitID: "ca-app-pub-3940256099942544/4411468910", request: GADRequest())
        interstitial?.fullScreenContentDelegate = self
      } catch {
        print("Failed to load interstitial ad with error: \(error.localizedDescription)")
      }
    }
  }

  /// Tells the delegate that the ad failed to present full screen content.
  func ad(_ ad: GADFullScreenPresentingAd, didFailToPresentFullScreenContentWithError error: Error) {
    print("Ad did fail to present full screen content.")
  }

  /// Tells the delegate that the ad will present full screen content.
  func adWillPresentFullScreenContent(_ ad: GADFullScreenPresentingAd) {
    print("Ad will present full screen content.")
  }

  /// Tells the delegate that the ad dismissed full screen content.
  func adDidDismissFullScreenContent(_ ad: GADFullScreenPresentingAd) {
    print("Ad did dismiss full screen content.")
  }
}

SwiftUI

Assign the fullScreenContentDelegate property to the returned ad:

interstitialAd?.fullScreenContentDelegate = self
InterstitialViewModel.swift

Implement the protocol:

func adDidRecordImpression(_ ad: GADFullScreenPresentingAd) {
  print("\(#function) called")
}

func adDidRecordClick(_ ad: GADFullScreenPresentingAd) {
  print("\(#function) called")
}

func ad(
  _ ad: GADFullScreenPresentingAd,
  didFailToPresentFullScreenContentWithError error: Error
) {
  print("\(#function) called")
}

func adWillPresentFullScreenContent(_ ad: GADFullScreenPresentingAd) {
  print("\(#function) called")
}

func adWillDismissFullScreenContent(_ ad: GADFullScreenPresentingAd) {
  print("\(#function) called")
}

func adDidDismissFullScreenContent(_ ad: GADFullScreenPresentingAd) {
  print("\(#function) called")
  // Clear the interstitial ad.
  interstitialAd = nil
}
InterstitialViewModel.swift

Objective-C

@import GoogleMobileAds;
@import UIKit;

@interface ViewController () <GADFullScreenContentDelegate>

@property(nonatomic, strong) GADInterstitialAd *interstitial;

@end

@implementation ViewController

- (void)viewDidLoad {
  [super viewDidLoad];
  GADRequest *request = [GADRequest request];
  [GADInterstitialAd loadWithAdUnitID:@"ca-app-pub-3940256099942544/4411468910"
      request:request
      completionHandler:^(GADInterstitialAd *ad, NSError *error) {
    if (error) {
      NSLog(@"Failed to load interstitial ad with error: %@", [error localizedDescription]);
      return;
    }
    self.interstitial = ad;
    self.interstitial.fullScreenContentDelegate = self;
  }];
}

/// Tells the delegate that the ad failed to present full screen content.
- (void)ad:(nonnull id<GADFullScreenPresentingAd>)ad
didFailToPresentFullScreenContentWithError:(nonnull NSError *)error {
    NSLog(@"Ad did fail to present full screen content.");
}

/// Tells the delegate that the ad will present full screen content.
- (void)adWillPresentFullScreenContent:(nonnull id<GADFullScreenPresentingAd>)ad {
    NSLog(@"Ad will present full screen content.");
}

/// Tells the delegate that the ad dismissed full screen content.
- (void)adDidDismissFullScreenContent:(nonnull id<GADFullScreenPresentingAd>)ad {
  NSLog(@"Ad did dismiss full screen content.");
}

GADInterstitialAd is a one-time-use object. This means that once an interstitial ad is shown, it cannot be shown again. A best practice is to load another interstitial ad in the adDidDismissFullScreenContent: method on GADFullScreenContentDelegate so that the next interstitial ad starts loading as soon as the previous one is dismissed.

Display the ad

Interstitials should be displayed during natural pauses in the flow of an app. Between levels of a game is a good example, or after the user completes a task.

Swift

guard let interstitial = interstitial else {
  return print("Ad wasn't ready.")
}

// The UIViewController parameter is an optional.
interstitial.present(fromRootViewController: nil)

SwiftUI

Listen to UI events in the view to determine when to show the ad.

var body: some View {
  // ...
  }
  .onChange(of: countdownTimer.isComplete) { newValue in
    showGameOverAlert = newValue
  }
  .alert(isPresented: $showGameOverAlert) {
    Alert(
      title: Text("Game Over"),
      message: Text("You lasted \(countdownTimer.countdownTime) seconds"),
      dismissButton: .cancel(
        Text("OK"),
        action: {
          viewModel.showAd()
        }))
InterstitialContentView.swift

Present the interstitial ad from the view model:

func showAd() {
  guard let interstitialAd = interstitialAd else {
    return print("Ad wasn't ready.")
  }

  interstitialAd.present(fromRootViewController: nil)
}
InterstitialViewModel.swift

Objective-C

if (self.interstitial) {
  // The UIViewController parameter is nullable.
  [self.interstitial presentFromRootViewController:nil];
} else {
  NSLog(@"Ad wasn't ready");
}

Best practices

Consider whether interstitial ads are the right type of ad for your app.
Interstitial ads work best in apps with natural transition points. The conclusion of a task within an app, like sharing an image or completing a game level, creates such a point. Because the user is expecting a break in the action, it's easy to present an interstitial ad without disrupting their experience. Make sure you consider at which points in your app's workflow you'll display interstitial ads and how the user is likely to respond.
Remember to pause the action when displaying an interstitial ad.
There are a number of different types of interstitial ads: text, image, video, and more. It's important to make sure that when your app displays an interstitial ad, it also suspends its use of some resources to allow the ad to take advantage of them. For example, when you make the call to display an interstitial ad, be sure to pause any audio output being produced by your app. You can resume playing sounds in the adDidDismissFullScreenContent: event handler, which will be invoked when the user has finished interacting with the ad. In addition, consider temporarily halting any intense computation tasks (such as a game loop) while the ad is being displayed. This will ensure that the user doesn't experience slow or unresponsive graphics or stuttered video.
Allow for adequate loading time.
Just as it's important to make sure you display interstitial ads at an appropriate time, it's also important to make sure the user doesn't have to wait for them to load. Loading the ad in advance before you intend to show can ensure that your app has a fully loaded interstitial ad at the ready when the time comes to display one.
Don't flood the user with ads.
While increasing the frequency of interstitial ads in your app might seem like a great way to increase revenue, it can also degrade the user experience and lower clickthrough rates. Make sure that users aren't so frequently interrupted that they're no longer able to enjoy the use of your app.
Don't use the load completion callback to show the interstitial.
This can cause a poor user experience. Instead, pre-load the ad before you need to show it. Then check the canPresentFromRootViewController:error: method on GADInterstitialAd to find out if it is ready to be shown.

Additional resources

Examples on GitHub

View the full interstitial ads examples in your preferred language:

Mobile Ads Garage video tutorials

Success stories

Next steps