Answering a person, run by Google.

What is Google-NotebookLM? The fetcher NotebookLM uses to read pages people add as sources. Verifiable by IP ranges and reverse DNS.

Run by Google.
Purpose: Answering a person. A visit means a person asked an AI assistant something, and the assistant opened this page to answer.
robots.txt name: Google-NotebookLM.
Verifiable by IP ranges and reverse DNS.

At a glance, the facts in one table.

Google-NotebookLM at a glance. Taken from SenseGap's open bot directory, the same data that sorts every visit in the dashboard.

Google-NotebookLM facts
	Google-NotebookLM
Operator	Google
Purpose	Answering a person
User agent contains	`Google-NotebookLM`
robots.txt name	`Google-NotebookLM`
Verification	IP ranges + Reverse DNS
Documentation	None listed

Purpose, what it does and why it came.

What Google-NotebookLM does. SenseGap sorts every visit by purpose. Google-NotebookLM is in the Answering a person group.

Google-NotebookLM is the fetcher Google's NotebookLM uses to read a web page that a person added as a source.

What a visit means

A visit means a person asked an AI assistant something, and the assistant opened this page to answer. It is the one kind of AI visit that implies a real question behind it.

That is why SenseGap pays close attention to this kind of visit. It groups the pages assistants open together to estimate what people likely asked, always labeled as an estimate. Nobody can see the actual questions. How it works.

Detection, the header SenseGap matches.

How SenseGap recognizes Google-NotebookLM. By its User-Agent header. A separate check then decides whether the visit is real.

Every request carries a User-Agent header naming the software that sent it. SenseGap counts a request as Google-NotebookLM when that header contains Google-NotebookLM, in any letter case. The header is plain text, so any script can copy it. Matching the name is where recognition starts, not where trust starts.

Pattern matched against User-Agent

/Google-NotebookLM/i

Verification, how to tell a real visit from a fake.

How to verify Google-NotebookLM. Google publishes its IP ranges and DNS names, so a real visit can be proven.

How we verify bots

IP ranges

user-triggered-fetchers.json

Published by Google at developers.google.com. A real Google-NotebookLM visit comes from an address in one of these lists.

Open the list

IP ranges

user-triggered-fetchers-google.json

Published by Google at developers.google.com. A real Google-NotebookLM visit comes from an address in one of these lists.

Open the list

SenseGap

Checked on every visit

SenseGap runs both checks on every visit that claims to be Google-NotebookLM, IP ranges first, then reverse DNS confirmed by a forward lookup. A pass is marked Real. A visit that sends the name and fails is marked Fake, and stays out of your other reports.

01
Look up the visiting address
Run a reverse DNS lookup on the IP address the request came from. It returns a hostname.
02
Check the hostname
The hostname must end in .googlebot.com, .google.com or .googleusercontent.com. Anything else is not Google-NotebookLM.
```
*.googlebot.com
*.google.com
*.googleusercontent.com
```
03
Look the hostname up again
Run a forward lookup on that hostname. It must return the same IP address, otherwise the reverse record could have been set by anyone.

The same check from a terminal

$ host <visiting-ip>
… domain name pointer <hostname>.googlebot.com.

$ host <hostname>.googlebot.com
<hostname>.googlebot.com has address <visiting-ip>

robots.txt, rules you can copy.

Block or allow Google-NotebookLM in robots.txt. Its robots.txt name is Google-NotebookLM. Paste a group into the robots.txt at your site's root.

Block the whole site

User-agent: Google-NotebookLM
Disallow: /

Allow the whole site

User-agent: Google-NotebookLM
Allow: /

Block one folder

User-agent: Google-NotebookLM
Disallow: /private/

One rule catches people out. Under the robots.txt standard (RFC 9309), a crawler that finds a group naming it follows only that group and ignores your User-agent: * rules. If you add a Google-NotebookLM group, repeat in it anything from the catch-all group you still want applied.

robots.txt is a request, not a lock. To enforce a block, match the User-Agent header at your server or CDN. In nginx:

Enforce it at the server

# nginx, inside a server block
if ($http_user_agent ~* "Google-NotebookLM") {
    return 403;
}

SenseGap reads your robots.txt and shows, bot by bot, what you allow and which bots fetched pages you disallowed. See what you get.

Trade-off, what blocking changes.

Should you block Google-NotebookLM? It depends on what you want from Google. Here is what each choice means.

If you allow it
The assistant can read your page while it answers, quote it and link to it.
If you block it
The assistant cannot open your page when someone asks, so it answers from other sources, or from what it already knows about you.

Google, every bot it runs.

More bots from Google. Google runs 8 bots in the directory, each with its own job.

Answering a person, other bots with the same job.

Google-NotebookLM, answered plainly

What is Google-NotebookLM?

Google-NotebookLM is the fetcher Google's NotebookLM uses to read a web page that a person added as a source.

Who runs Google-NotebookLM?

Google. SenseGap's directory has no documentation link for it yet.

What does a visit from Google-NotebookLM mean?

A visit means a person asked an AI assistant something, and the assistant opened this page to answer. It is the one kind of AI visit that implies a real question behind it.

What user agent does Google-NotebookLM use?

Its User-Agent header contains "Google-NotebookLM". SenseGap matches it regardless of letter case.

How do I block Google-NotebookLM?

Add "User-agent: Google-NotebookLM" followed by "Disallow: /" to your robots.txt. robots.txt is a request, not a lock; to enforce it, block the user agent at your server or CDN.

How do I know a visit is really Google-NotebookLM?

Google publishes the IP ranges Google-NotebookLM uses (user-triggered-fetchers.json and user-triggered-fetchers-google.json), so check that the visiting address falls inside one of them. You can also run a reverse DNS lookup on the address: the hostname must end in .googlebot.com, .google.com or .googleusercontent.com, and a forward lookup of that hostname must return the same address. SenseGap runs these checks on every visit.

Does Google publish IP ranges for Google-NotebookLM?

Yes, at https://developers.google.com/static/search/apis/ipranges/user-triggered-fetchers.json and https://developers.google.com/static/search/apis/ipranges/user-triggered-fetchers-google.json. A real visit comes from an address in one of these lists.

What happens if I block Google-NotebookLM?

The assistant cannot open your page when someone asks, so it answers from other sources, or from what it already knows about you.

See whether Google-NotebookLM visits your site. Every visit checked, with the pages it read and an estimate of what people asked.

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