What is GoogleAgent-Mariner? AI crawler guide

GoogleAgent-Mariner by Google: Google AI agent token associated with browser-style task execution. Check its reported user-agent, robots.txt behavior, source, and verification guidance.

Google AI agent token associated with browser-style task execution.

What is GoogleAgent-Mariner?

GoogleAgent-Mariner is a web crawler user-agent token operated by Google. It is associated with AI agent functionality that performs browser-style task execution, meaning it can interact with web pages in ways that go beyond traditional indexing. When this token appears in server logs, it signals that an automated agent, rather than a standard search crawler, is navigating the site. The token is documented in community-maintained resources, but Google has not published official documentation for it. Its posture toward robots.txt compliance is unverified, so site owners should not assume it will honor exclusion rules without testing.

What it's for

For site owners, a hit from GoogleAgent-Mariner may indicate that an AI agent is using the site to perform tasks on behalf of a user, such as gathering information or completing multi-step actions. This differs from indexing crawlers that collect data for search results. The presence of this agent could affect server load, content consumption, and how your site's data is utilized in AI-driven services. Understanding this distinction helps you decide whether to allow or block such interactions based on your site's policies and resource considerations.

GoogleAgent-Mariner access decides whether Google can fetch your pages. Whether those pages get used in generated answers is a separate question, so track your presence in Google's AI results rather than treating crawl volume as visibility.

How to handle GoogleAgent-Mariner

If you wish to prevent GoogleAgent-Mariner from accessing your site, you can add a robots.txt rule targeting its user-agent token. Because its compliance posture is unverified, blocking may not be guaranteed, but it is the primary available control. Monitor your logs for this token to assess its activity and adjust your policy as needed. Consider the potential benefits of allowing AI agents to interact with your site, such as enabling new user experiences, against any concerns about resource usage or data exposure.

robots.txt rule

User-agent: GoogleAgent-Mariner Disallow: /

Blocking cost

Blocking GoogleAgent-Mariner may prevent your site from being used in AI agent tasks, which could reduce visibility in AI-driven search, answer generation, citation, or training scenarios, but the exact impact is uncertain due to the unverified compliance posture.

Examples

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Frequently Asked Questions

What does GoogleAgent-Mariner do?

GoogleAgent-Mariner is a user-agent token used by Google's AI agents to perform browser-style tasks on websites, such as navigating pages, filling forms, or completing multi-step interactions, rather than just indexing content.

How is GoogleAgent-Mariner different from Googlebot?

Googlebot primarily crawls and indexes web pages for Google Search, while GoogleAgent-Mariner is associated with AI agents that execute tasks and interact with sites in a more dynamic, user-like manner.

Does GoogleAgent-Mariner obey robots.txt?

The robots.txt compliance posture of GoogleAgent-Mariner is unverified. While you can set rules for it, there is no guarantee it will honor them, so blocking may not be fully effective.

Should I block GoogleAgent-Mariner?

Blocking depends on whether you want AI agents to use your site. If you are concerned about resource usage or data exposure, you may choose to block it, but this could also limit your site's participation in AI-driven services.

Where can I find official documentation for GoogleAgent-Mariner?

There is no official documentation from Google for this token. Information is available from community-maintained sources, but its behavior and compliance are not formally documented.

Data & Sources