GoogleAgent-Mariner user agent
Operated by Google
GoogleAgent-Mariner is the user agent reported for Project Mariner, Google DeepMind's browser agent.
The GoogleAgent-Mariner bot at a glance
- GoogleAgent-Mariner is operated by Google and loads web pages in a browser to complete tasks on behalf of a user.
- The robots.txt token for GoogleAgent-Mariner is GoogleAgent-Mariner.
- Blocking an AI agent has no effect on search rankings.
- GoogleAgent-Mariner robots.txt support: Not documented.
- Recommendation for Generative Engine Optimization (GEO): Allow.
What is GoogleAgent-Mariner?
Project Mariner operates a browser to complete tasks for users, such as filling forms or comparing products.
Google’s fetcher documentation now lists Google-Agent for its AI agents.
Should you block GoogleAgent-Mariner?
Allow GoogleAgent-Mariner unless it causes a measurable load problem.
| Effect on search rankings | Blocking an AI agent has no effect on search rankings. |
|---|---|
| Effect on AI visibility | Blocking stops agents from completing tasks on your website for their users, which can cost bookings or sales that agents would have made. |
| Follows robots.txt | Not documented |
| Recommendation | Allow |
How to block or allow GoogleAgent-Mariner
Put the robots.txt rule in the file at the root of every domain and subdomain, for example https://example.com/robots.txt. The token GoogleAgent-Mariner is matched case-insensitively. robots.txt alone may not stop GoogleAgent-Mariner, so add the Nginx, Apache or Cloudflare rule as well.
robots.txt: block
# Block GoogleAgent-Mariner
User-agent: GoogleAgent-Mariner
Disallow: /robots.txt: allow
# Allow GoogleAgent-Mariner
User-agent: GoogleAgent-Mariner
Allow: /robots.txt: partial
# Keep GoogleAgent-Mariner out of private areas only
User-agent: GoogleAgent-Mariner
Disallow: /wp-admin/
Disallow: /cart/
Disallow: /checkout/
Disallow: /my-account/
Allow: /Nginx
# Nginx: return 403 to GoogleAgent-Mariner
if ($http_user_agent ~* "(GoogleAgent\-Mariner)") {
return 403;
}Apache
# Apache .htaccess: return 403 to GoogleAgent-Mariner
RewriteEngine On
RewriteCond %{HTTP_USER_AGENT} (GoogleAgent\-Mariner) [NC]
RewriteRule .* - [F,L]Cloudflare WAF
# Cloudflare > Security > WAF > Custom rule, action: Block
(http.user_agent contains "GoogleAgent-Mariner")How to verify real GoogleAgent-Mariner traffic
Google publishes no IP list or reverse DNS pattern for GoogleAgent-Mariner, so the user agent cannot be verified. Anyone can send the same string. Rate-limit unusual volume instead of trusting the name.
How to find GoogleAgent-Mariner in your server logs
Search the web server access log for the token. The command below counts GoogleAgent-Mariner requests per URL on Nginx or Apache.
grep -i "GoogleAgent-Mariner" access.log | awk '{print $7}' | sort | uniq -c | sort -rn | head -20For a full report per AI bot, upload the log to the AI Log File Analyzer, a free tool by Justin Hà.
GoogleAgent-Mariner user agent string
The full user agent Google publishes for GoogleAgent-Mariner. Version numbers such as Chrome/W.X.Y.Z change over time, so match the token, not the whole string.
Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko; compatible; GoogleAgent-Mariner) Chrome/142.0.7444.162 Safari/537.36GoogleAgent-Mariner FAQ
GoogleAgent-Mariner identifies itself with the robots.txt token "GoogleAgent-Mariner". A typical request header reads: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko; compatible; GoogleAgent-Mariner) Chrome/142.0.7444.162 Safari/537.36
Google has not documented how GoogleAgent-Mariner treats robots.txt. Add a robots.txt rule and back it with a server rule if the traffic matters to you.
Blocking an AI agent has no effect on search rankings. Blocking stops agents from completing tasks on your website for their users, which can cost bookings or sales that agents would have made.
Add two lines to the robots.txt file at the root of each domain and subdomain: "User-agent: GoogleAgent-Mariner" followed by "Disallow: /". The token is case-insensitive. Changes can take up to 24 hours to be picked up.
Not reliably. Google publishes no IP list or reverse DNS pattern for GoogleAgent-Mariner, so anyone can send the same user agent. Rate-limit unusual volume instead of trusting the name.
Search your server access log for "GoogleAgent-Mariner", for example with: grep -i "GoogleAgent-Mariner" access.log. The AI Log File Analyzer by Justin Hà counts visits per AI bot from an uploaded log file.
Sources: Public bot registry. Last reviewed by Justin Hà.
See which of these bots actually reach your website
The AI Log File Analyzer by Justin Hà counts visits from GPTBot, ClaudeBot, PerplexityBot and other AI crawlers in your server log, for free. The GEO Technical Package sets up robots.txt, llms.txt and crawler access for AI search.
