Does Mozilla-Tabstack respect robots.txt?

Yes. The operator documents that Mozilla-Tabstack reads robots.txt and follows Disallow rules for its own token. Rules take effect on the next fetch of the file, which can be hours or days after you publish them.

How do I block Mozilla-Tabstack?

Add the Mozilla-Tabstack token to robots.txt with Disallow: /. If the crawler ignores robots.txt, match the user agent at your CDN or reverse proxy and return 403 there instead.

IPScanner

Data scrapers and resellers

Mozilla-Tabstack

Q: How do I verify a request really came from Mozilla-Tabstack?

You cannot, at least not from the request itself. No IP range file and no reverse-DNS convention have been published for this agent. The user-agent string is the only signal, and any client can send it, so treat a match as a claim rather than proof. Compare the source IP against hosting and datacenter ranges instead, and rate limit anything that behaves like a crawler.

Mozilla-Tabstack is a bot operated by Mozilla that crawls pages into a dataset that is then reused or sold. Tabstack is a web intelligence API for AI agents. It is documented as honouring robots.txt, but no IP range list or reverse-DNS convention is published, so a request carrying this user agent cannot be proven genuine.

Mozilla-Tabstack at a glance

Reference data for the Mozilla-Tabstack crawler
User agent	`Mozilla-Tabstack` Token only. The operator has not published a full user-agent string, so match on the substring rather than an exact header.
Operator	Mozilla
Purpose	Data scrapers and resellers
Respects robots.txt	Yes, documented
Verification method	None published, user agent only No IP range file and no reverse-DNS convention have been published for this agent. The user-agent string is the only signal, and any client can send it, so treat a match as a claim rather than proof.
Crawl pattern	On demand via API.
Robots.txt tokens	`Mozilla-Tabstack`
Operator documentation	None published

Tabstack is a web intelligence API for AI agents. It extracts structured data from web pages and makes it available to AI agents.

robots.txt

Allow or block Mozilla-Tabstack

Paste one of these into the robots.txt file at the root of your domain. Rules are per token, so a block on one crawler leaves every other bot untouched.

Block Mozilla-Tabstack

User-agent: Mozilla-Tabstack
Disallow: /

Blocks every path for this crawler only.

Allow Mozilla-Tabstack

User-agent: Mozilla-Tabstack
Allow: /

Explicit allow. Useful when a wildcard rule above it would otherwise catch this crawler.

Allow, except the pages you never want quoted

User-agent: Mozilla-Tabstack
Allow: /
Disallow: /account/
Disallow: /checkout/
Disallow: /search

Edit the Disallow paths to match your own account, checkout and search URLs.

What blocking actually costs you

Blocking Mozilla-Tabstack stops your content being packaged and resold to third parties. Whoever bought earlier crawls still has them.

Block every crawler in the directory at once

Verification

Is that really Mozilla-Tabstack?

A user-agent header is a string the client chooses. Scrapers copy Mozilla-Tabstack precisely because site owners allow it. No IP range file and no reverse-DNS convention have been published for this agent. The user-agent string is the only signal, and any client can send it, so treat a match as a claim rather than proof.

Paste the IP address from your access log below. You will see whether it belongs to a hosting provider, a residential proxy pool or a Tor exit, plus the ASN that announces it, which is what tells you whether the claim holds up.

Datacenter IP detectionNearly every real AI crawler egresses from cloud ranges. A residential IP claiming to be one is the first thing to check.IP reputation checkSee whether the address behind a fake crawler hit has a history of abuse elsewhere.Residential proxy detectionScrapers that get blocked by user agent often come back through residential proxy pools.

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Agentscan

Identify crawlers automatically instead of by hand

Agentscan checks a request against published crawler ranges, reverse DNS and hosting data, then returns a verdict your edge can act on. One call per request, no range files to keep up to date.

How Agentscan works API reference Pricing What is my IP

FAQ