How Creative Validator works

Creative Validator is a free tool for checking HTML5 ad bundles, third-party ad tags and VAST before trafficking. It brings file checks and browser observations into reports that help ad operations teams explain a problem and decide what to test next.

Creative Validator is an independent diagnostic tool. It is not a Google product or a certification service for any ad platform.

Methodology updated October 6, 2026.

What a scan checks

• HTML5 bundles: inspect ZIP contents, HTML entry points, dimensions, file weight, asset references and click handling. Browser checks add observations about rendering and runtime behavior. Start with the HTML5 creative validator.
• Third-party tags: inspect submitted tag code and observe execution in a test browser, including requests, redirects and errors exposed by the scan. Start with the tag tester.
• VAST: inspect the XML response, follow supported wrappers and examine media and tracking declarations. Some checks depend on whether the remote endpoint can be reached. Read the VAST validator overview.

Available checks depend on the input, scan options and selected limits. A static finding describes the supplied files or code; a runtime observation describes what happened in that particular test session. Read the individual findings alongside the overall result.

What a pass means

A pass means the completed checks did not find a blocking issue under the tested conditions. It does not guarantee that Google Ad Manager or another platform will accept, serve or approve the creative.

Upload processors, account settings, platform policies and serving environments can impose additional requirements. A result also cannot establish performance across every device, browser, consent state or network connection.

If a request times out, access is blocked or a check is inconclusive, preserve that uncertainty. An unavailable observation is not evidence that the creative works correctly.

How to use the evidence

1. Keep the exact original file or tag, and record the scan settings and time. Compare the detailed findings with the target platform's current requirements.
2. Make a focused change, then scan the changed asset again. A repaired copy must be tested separately from the original.
3. Upload and preview the individual creative in the intended platform. Confirm the rendered content and click destination there.
4. If the platform rejects a locally passing file, collect the exact error and relevant identifiers for its support team. Our GAM upload troubleshooting guide explains how to separate a bundle defect from an unexplained processor rejection.

Sources and maintenance

The reference library links to platform documentation for specifications and macros. Those external requirements can change; the platform's current documentation takes precedence over an older guide or saved report.

Use the HTML5 specifications reference and click macro reference to check the source behind a requirement. The changelog records product updates, and the API documentation describes the available interfaces.

Published platform requirements, local performance budgets and test observations are different kinds of evidence. Local request-count, script-count and load-time budgets are diagnostic heuristics, not universal IAB requirements or guaranteed platform rejection thresholds.

• GAM HTML5 guidelines: package structure, dimensions and click handling.
• GAM macro reference: click encoding and vendor-specific consent macros.
• IAB New Ad Portfolio guide: format-specific creative guidance, distinct from the site's local runtime budgets.
• IAB Tech Lab VAST: video ad declarations and tracking structure.

See privacy and scan data for retention, report access and the external requests scans can generate.

To make a finding reproducible when sharing it with a colleague or vendor, include the check name, expected behavior, actual behavior and the smallest relevant example. Remove credentials and other private information before sharing.