VAST Video Ad Preview

How the Video Preview Works

When you test a VAST tag in VAST Tester Tool, we generate a live video preview so you can see exactly how the ad would render in a real player environment. The preview is powered by the Google IMA SDK, which is one of the most widely used ad playback frameworks in the industry.

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Step-by-Step Process

1. Player Initialization

   • When you enter a VAST tag and click Preview, our tool loads a standard HTML5 video player embedded with the Google IMA SDK.
   • The SDK is responsible for handling all the ad playback logic, including fetching, parsing, and rendering the creative.

2. VAST Tag Request

   • The SDK sends a request to the ad server using the exact VAST tag you provided.
   • Any macros in the tag (such as timestamp, cachebuster, or device_id) are resolved or passed as-is, depending on the ad server setup.

3. Response Handling

   • The ad server returns a VAST XML response, which may include media files, tracking pixels, and other instructions (wrappers, companions, skip settings, etc.).
   • The SDK validates the response and selects the appropriate media file to play based on the preview environment (desktop browser).

4. Ad Playback

   • The chosen creative (video ad file) is loaded and played inside the preview window.
   • You will see the same visual experience that an end user would: the ad starts, plays for its duration, and any interactive elements (like skip buttons, clickthrough overlays, or companion banners) are displayed if available.

5. Event Tracking

   • Behind the scenes, the SDK also fires tracking beacons (impression, quartiles, complete, errors, etc.) exactly as they would in a production environment.
   • Our tester logs these events for you so you can confirm whether all tracking is firing correctly.

6. Ad Info Display

   • The ad information (such as Duration, Format, Resolution, Ad System, Interactive, Companion Ads and Clickthrough URL) is displayed alongside the video player for your reference.

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What You’ll See as a User

• A video ad plays in the preview window, starting automatically.
• If the ad is skippable, the skip button will appear after the defined delay.
• Clickthrough actions (e.g., tapping on the ad) will open a new tab with the advertiser’s landing page.
• Companion creatives, if defined, may appear in the results card under the player.
• Once the ad completes, the player resets and is ready for another test.