GTM Debug Runner is a free Chrome extension designed for developers, analysts, and technical marketing teams working with Google Tag Manager. This tool enhances Google Tag coverage by automatically invoking untagged pages identified in CSV exports from Google Tag Coverage. It appends the gtm_debug parameter to each URL, facilitating a systematic approach to validating tag coverage without the need for manual navigation through numerous URLs.

The extension operates in conjunction with the Google Tag Assistant Companion, enabling automated sequential page calls during an active debug session. Users can monitor progress, estimated time of arrival, and status transparently, while also having the option to pause, resume, or abort the process as needed. Key features include importing CSV exports, filtering untagged pages, and maintaining persistent status across domains, making it an essential tool for optimizing Google Tag Manager implementations.