What is Iframely? Iframely's link preview crawler
The Iframely Preview Agent fetches a URL only after someone shares it in an app built by an Iframely customer, to show a link preview or embed. Iframely says it reads only page metadata and does not follow links.
32 of the 1662 major websites we measure block Iframely in robots.txt (2%). 5 of those sites name it directly in their robots.txt; the rest are covered by a wildcard rule.
Key facts
| Fact | Detail |
|---|---|
| Operator | Iframely |
| Used for | Link previews in Iframely customers' apps |
| Type | Link preview. Fetches a page to show a preview when someone shares its link. It isn't counted in the AI crawler figures. |
| robots.txt token | Iframely |
| Operator's documentation | Read it here |
What blocking Iframely does
Iframely says it does not check robots.txt for these preview requests, because the agent fetches only the URL a person supplied; its robots.txt rules apply to its separate processing and training agents.
How to allow or block Iframely
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: Iframely Disallow: /
User-agent: Iframely Allow: /
Iframely user agent string
Iframely's page doesn't list a full string, so look for Iframely in the user agent field of your logs.
How to verify a request is really Iframely
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 Iframely.
How to whitelist Iframely 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 Iframely afterwards.
On Cloudflare, also check AI Crawler and Agent access policies, which can block search, agent and training traffic across a site.
Why Iframely 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 ~* "Iframely") {
return 403;
}Who blocks Iframely, by sector
| Sector | Sites measured | Blocking | Share |
|---|---|---|---|
| Social and media platforms | 115 | 11 | 10% |
| Reference and research | 114 | 4 | 4% |
| News publishers | 182 | 5 | 3% |
| AI companies | 128 | 3 | 2% |
| Technology media | 126 | 3 | 2% |
| E-commerce and retail | 92 | 1 | 1% |
| Finance and business media | 94 | 1 | 1% |
| Government and institutions | 98 | 1 | 1% |
| Hosting and infrastructure | 98 | 1 | 1% |
| SaaS platforms | 196 | 2 | 1% |
| Developer references | 159 | 0 | 0% |
| Health publishers | 88 | 0 | 0% |
| SEO and marketing tools | 86 | 0 | 0% |
| Travel | 86 | 0 | 0% |
Sites blocking Iframely
academia.edu, afterpay.com, consilium.europa.eu, devclass.com, disneyplus.com, distill.pub, eluniversal.com.mx, facebook.com, flickr.com, fortinet.com, hackernoon.com, imdb.com, instacart.com, instagram.com, linguee.com, lobste.rs, magento.com, meta.ai, netflix.com, news.com.au, pinterest.com, poe.com, reddit.com, sap.com, sciencedirect.com, theregister.com, thesun.co.uk, thetimes.co.uk, threads.net, todayonline.com, wordreference.com, x.com.
Sites that allow Iframely by name
barrons.com, marketwatch.com, reuters.com, wsj.com, zeit.de.
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. "Iframely block rate across major websites." Measured 12 November 2026. https://www.indexhalo.com/ai-crawlers/iframely/
<a href="https://www.indexhalo.com/ai-crawlers/iframely/">Iframely block rate across major websites, IndexHalo</a>