VAST Tag Media File Validator

Check VAST tag media files for proper formatting and resolutions.

Enter Your VAST Tag URL to validate media files

Validating the VAST tag for the profile: Media Files

Use this page to preview and debug the VAST tag in our online VAST tester. View the VAST XML, video ad player preview, tracking events, and more.

How Our Online VAST Tester Works

  • Paste your VAST tag URL into the input field.
  • Click the "Validate" button to start the validation process.
  • Review the validation results and fix any issues using the provided feedback.

What is a VAST Tester?

A VAST tester is a tool that loads your VAST XML ad tag and simulates how a video player would interpret it. Instead of guessing whether your tags will deliver correctly, you can test them online and spot issues before launch.

VAST Video player - Ad Preview and Inspector

VAST Tag Preview & Validator

Once you paste your VAST tag URL and click Validate, your VAST tag preview will appear here. Our VAST online validator instantly loads your ad response, showing a live video ad playback, media file details, and tracking events.

Video ad previews are powered by the Google IMA SDK.

Our VAST tester helps you:

  • Debug and troubleshoot VAST errors
  • Preview video ads in real-time
  • Inspect media assets and tracking pixels
  • Verify compliance with VAST standards
  • How to fix common VAST errors detected during validation

By running your tags through the preview, you can be confident your video ads will deliver correctly before launching campaigns.

VAST Validation Results

What We Test For

When you run a test in our VAST Tag Tester, we check your VAST or VMAP tag for the following common issues and best practices

Media Files

Ensures media files are present and properly formatted.

We support various media file types including MP4, WebM, and Ogg.

Why we test media files

Media files are the core of any video ad. Testing ensures the file type, codec, bitrate, and delivery method meet player compatibility standards, preventing playback errors and poor viewing experiences.

Learn about media file requirementsView all tests