What is Webzio-Extended? Webz.io's AI crawler
Webzio-Extended takes the content Webzio collects and tags each item as usable or not usable for AI and machine-learning training.
153 of the 1662 major websites we measure block Webzio-Extended in robots.txt (9%), making it number 18 of the 36 AI crawlers we track for how often it is blocked. 123 of those sites name it directly in their robots.txt; the rest are covered by a wildcard rule.
Key facts
| Fact | Detail |
|---|---|
| Operator | Webz.io |
| Used for | AI and machine-learning training data |
| Type | Model training. Collects content that may be used to train AI models. Blocking it does not usually remove a site from AI search. |
| robots.txt token | Webzio-Extended |
| Operator's documentation | Read it here |
What blocking Webzio-Extended does
Webz.io says its crawlers adhere to robots.txt exclusions, and that site owners can block each by its own token.
How to allow or block Webzio-Extended
Add one of these groups to the robots.txt file at the root of your domain. It is a stated preference that well-behaved crawlers read, not an enforcement mechanism.
User-agent: Webzio-Extended Disallow: /
User-agent: Webzio-Extended Allow: /
To see whether your own site lets Webzio-Extended in, and which rule decides it, run the free AI crawler checker.
Webzio-Extended user agent string
Webz.io's page doesn't list a full string, so look for Webzio-Extended in the user agent field of your logs.
How to verify a request is really Webzio-Extended
Anyone can put a crawler's name in a user agent string, so the name alone proves nothing. We did not find a published IP list or reverse DNS rule from Webz.io.
How to whitelist Webzio-Extended in a firewall or CDN
robots.txt only states a preference. A firewall, CDN or bot protection service can still refuse the request, and the crawler then gets an error even though robots.txt allows it.
- Check that no group in your robots.txt blocks it, using the rule above.
- Add an allow rule in your firewall or CDN that matches the name in the user agent. Keep the rule narrow, because anyone can copy a name.
- Check your server logs for a 200 response from Webzio-Extended afterwards.
On Cloudflare, also check AI Crawler and Agent access policies, which can block search, agent and training traffic across a site.
Why Webzio-Extended gets a 403 or 405 error
A 403 means the server refused the request, which usually points to a firewall or bot rule. A 405 means the server refused the request's method, so check any rule that only permits certain methods. A crawler that obeys robots.txt won't request a page it is told to avoid, so an error in your logs points to your server's configuration. To stop it deliberately at the server, this nginx rule returns a 403:
if ($http_user_agent ~* "Webzio-Extended") {
return 403;
}Which sites recently changed their rules for Webzio-Extended?
None that lasted since 17 August 2026. See the full change log.
Who blocks Webzio-Extended, by sector
| Sector | Sites measured | Blocking | Share |
|---|---|---|---|
| News publishers | 182 | 56 | 31% |
| Social and media platforms | 115 | 30 | 26% |
| Technology media | 126 | 22 | 17% |
| Health publishers | 88 | 12 | 14% |
| Finance and business media | 94 | 7 | 7% |
| Reference and research | 114 | 7 | 6% |
| E-commerce and retail | 92 | 5 | 5% |
| Travel | 86 | 3 | 3% |
| AI companies | 128 | 3 | 2% |
| Government and institutions | 98 | 2 | 2% |
| SaaS platforms | 196 | 4 | 2% |
| Hosting and infrastructure | 98 | 1 | 1% |
| SEO and marketing tools | 86 | 1 | 1% |
| Developer references | 159 | 0 | 0% |
Sites blocking Webzio-Extended
01net.com, abc.net.au, academia.edu, aftenposten.no, afterpay.com, aftonbladet.se, airbnb.com, al.com, allrecipes.com, amazon.ca, amazon.co.uk, amazon.com, amazon.de, architecturaldigest.com, arstechnica.com, asahi.com, azcentral.com, babycenter.com, barrons.com, behance.net, bild.de, bonappetit.com, bostonglobe.com, canva.com, cio.com, cleveland.com, cnn.com, cntraveler.com, congress.gov, consilium.europa.eu, contentmarketinginstitute.com, corriere.it, dailymail.co.uk, dallasnews.com, darkreading.com, devclass.com, disneyplus.com, distill.pub, dn.se, drugs.com, dw.com, eluniversal.com.mx, epicurious.com, estadao.com.br, eurogamer.net, everydayhealth.com, ew.com, extremetech.com, facebook.com, fastcompany.com, flickr.com, fortinet.com, gamesindustry.biz, genius.com, gizmodo.com, globeandmail.com, gq.com, hackernoon.com, healthline.com, heise.de, and 93 more in the full dataset.
Sites that allow Webzio-Extended by name
deezer.com, foreignpolicy.com, pcmag.com, postman.com, statista.com.
Other Webz.io crawlers
Omgilibot (training dataset), Webzio (web data for AI).
See all 36 AI crawlers, the rule change log or the full study. Being reachable is only the first step: how AI search engines choose what to cite covers the rest.
Cite this data
You are welcome to quote or republish these figures. Please credit IndexHalo with a link to this page (CC BY 4.0). All our datasets are on the data page.
IndexHalo. "Webzio-Extended block rate across major websites." Measured 12 November 2026. https://www.indexhalo.com/ai-crawlers/webzio-extended/
<a href="https://www.indexhalo.com/ai-crawlers/webzio-extended/">Webzio-Extended block rate across major websites, IndexHalo</a>