▼ Summary

– Google rebranded NotebookLM to Gemini Notebook, updating its user agent from Google-NotebookLM to Google-GeminiNotebook with the old agent supported until August 2026.
– Gemini Notebook’s Discover Sources feature scrapes up to ten online articles per user query without permission, providing AI summaries and no referral traffic to source sites.
– The tool can repurpose uploaded content into audio podcasts or video explainers, potentially competing with the original source material online.
– User-triggered fetchers like Gemini Notebook do not obey robots.txt, but site owners can block them via firewall rules or .htaccess files, requiring updates for the new user agent.
– Project Mariner was retired in May 2026, and its mention was removed from Google’s user-triggered fetcher documentation.

Google has officially rebranded NotebookLM to Gemini Notebook, and with that change comes an important update to the list of Google user-triggered fetchers. For site owners and SEO professionals who have hardcoded the old user agent string in their robots.txt files, firewalls, or .htaccess configurations, there is a limited grace period. The legacy user agent, Google-NotebookLM, will stop functioning in August 2026, giving users only a few weeks to make the switch.

There are compelling reasons for website owners to consider blocking Gemini Notebook. The tool’s Discover Sources feature can scrape online articles without explicit permission from the site owner. It automatically pulls up to ten sources based on a user’s query or topic, generates an AI-powered summary, and delivers no referral traffic back to the original publishers. Additionally, Gemini Notebook’s audio and video overview features repurpose existing online content, turning it into podcast episodes or video explainers. If that generated content is later published online, it can directly compete with the original material for audience attention.

These functionalities are intentional parts of Gemini Notebook’s design. The tool automates the process of scraping unique content and transforming it into something new, all without attribution to the original source. Site owners who wish to block Gemini Notebook will need to update their firewalls and .htaccess files to maintain control over their content.

The rebrand from NotebookLM to Gemini Notebook is a name change only; the underlying functionality remains identical. Gemini Notebook acts as a research assistant, allowing users to upload documents that serve as ground truth for better answers, research, and learning. It is multimodal, meaning it can process content from YouTube and uploaded audio files. This multimodality works both ways: users can also convert uploaded documents into audio or video podcast episodes for easier learning.

For SEOs and website owners, the critical detail is that Gemini Notebook can fetch web pages for user research. This happens when a user pastes URLs or uses the Discover Sources feature, which automates finding and adding articles as research sources. These scrapers are classified as user-triggered fetchers, meaning they do not obey robots.txt directives. However, site owners can still block them by setting up a firewall rule or an .htaccess rule. Here is an example of an .htaccess rule:

“` RewriteEngine On

Block Google-GeminiNotebook

RewriteCond %{HTTPUSERAGENT} Google-GeminiNotebook [NC] RewriteRule ^ – [F,L] “`

Project Mariner has been completely retired as of May 2026, and Google has removed all references to it from its documentation. The old documentation mentioned Project Mariner as an example of a user-triggered agent, but that example has been deleted.

The other significant change is the complete removal of the old NotebookLM entry from Google’s documentation. The previous entry read:

“Google NotebookLM User-Agent in HTTP requests Google-NotebookLM Associated products The Google-NotebookLM fetcher requests individual URLs that NotebookLM users have provided as sources for their projects.”

This has been replaced with new documentation for Gemini Notebook:

“Gemini Notebook User-Agent in HTTP requests Mobile agent: Mozilla/5.0 (Linux; Android 10; K) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Mobile Safari/537.36 (compatible; Google-GeminiNotebook; +https://developers.google.com/crawling/docs/crawlers-fetchers/google-gemininotebook) Desktop agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/137.0.0.0 Safari/537.36 (compatible; Google-GeminiNotebook; +https://developers.google.com/crawling/docs/crawlers-fetchers/google-gemininotebook) Former agent (supported until August 2026): Google-NotebookLM Associated products: The Gemini Notebook fetcher requests individual URLs that Gemini Notebook users have provided as sources for their projects.”

The changelog advises: “If you hardcoded the old value in your code, update the string to avoid potential bugs. We will continue to support the old value to allow for a smooth transition.”

In summary, Google’s rebrand of NotebookLM to Gemini Notebook includes a documentation update that removes the old user agent and introduces the new one. Site owners using the old user agent to track or block Gemini Notebook activity have only a few weeks to update their firewalls or .htaccess files. Remember, user-triggered fetchers do not obey robots.txt. Robots.txt is not a directive; it is a request that crawlers can ignore. Therefore, there is no requirement for Gemini Notebook’s crawler to follow it. However, site owners can still effectively control access using a firewall or an .htaccess file.

(Source: Search Engine Journal)