What is SeznamBot? Seznam.cz's search crawler
SeznamBot is the crawler that fetches content for the Seznam.cz search engine.
35 of the 1662 major websites we measure block SeznamBot in robots.txt (2%). 27 of those sites name it directly in their robots.txt; the rest are covered by a wildcard rule.
Key facts
| Fact | Detail |
|---|---|
| Operator | Seznam.cz |
| Used for | Seznam.cz search |
| Type | Search engine. Builds a search engine's index. Listed here because people look it up beside AI crawlers. It isn't counted in the AI crawler figures. |
| robots.txt token | SeznamBot |
| Operator's documentation | Read it here |
What blocking SeznamBot does
Blocking SeznamBot keeps a site's pages out of Seznam.cz's crawl. Seznam also runs FreshBot, a faster crawler for fresh content, mostly on news sites.
How to allow or block SeznamBot
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: SeznamBot Disallow: /
User-agent: SeznamBot Allow: /
SeznamBot user agent string
The string Seznam.cz documents. Version numbers can change, so match on the name.
Mozilla/5.0 (compatible; SeznamBot/4.0; +https://o-seznam.cz/napoveda/vyhledavani/en/seznambot-crawler/)
How to verify a request is really SeznamBot
Anyone can put a crawler's name in a user agent string, so the name alone proves nothing. Seznam says its crawler addresses have reverse DNS names in the seznam.cz domain, starting with fulltextrobot-, and it publishes a list of SeznamBot address ranges.
How to whitelist SeznamBot 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 SeznamBot afterwards.
On Cloudflare, also check AI Crawler and Agent access policies, which can block search, agent and training traffic across a site.
Why SeznamBot 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 ~* "SeznamBot") {
return 403;
}Who blocks SeznamBot, by sector
| Sector | Sites measured | Blocking | Share |
|---|---|---|---|
| News publishers | 182 | 11 | 6% |
| Social and media platforms | 115 | 5 | 4% |
| Technology media | 126 | 5 | 4% |
| Government and institutions | 98 | 3 | 3% |
| Reference and research | 114 | 3 | 3% |
| AI companies | 128 | 2 | 2% |
| Finance and business media | 94 | 2 | 2% |
| E-commerce and retail | 92 | 1 | 1% |
| Hosting and infrastructure | 98 | 1 | 1% |
| SaaS platforms | 196 | 1 | 1% |
| SEO and marketing tools | 86 | 1 | 1% |
| Developer references | 159 | 0 | 0% |
| Health publishers | 88 | 0 | 0% |
| Travel | 86 | 0 | 0% |
Sites blocking SeznamBot
afterpay.com, azcentral.com, bundesregierung.de, consilium.europa.eu, devclass.com, digitaltrends.com, distill.pub, eluniversal.com.mx, finance.yahoo.com, flickr.com, fortinet.com, france24.com, golem.de, hackernoon.com, imdb.com, instacart.com, linguee.com, lobste.rs, magento.com, milenio.com, news.com.au, poe.com, reddit.com, reuters.com, sciencedirect.com, theguardian.com, theregister.com, thesun.co.uk, thetimes.co.uk, todayonline.com, usatoday.com, webmasterworld.com, who.int, wordreference.com, x.com.
Sites that allow SeznamBot by name
academia.edu, barrons.com, disneyplus.com, facebook.com, gsmarena.com, instagram.com, marketwatch.com, meta.ai, netflix.com, pinterest.com, salon.com, sap.com, threads.net, vimeo.com, wsj.com, zeit.de.
Other Seznam.cz crawlers
FreshBot (fresh content indexing).
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. "SeznamBot block rate across major websites." Measured 12 November 2026. https://www.indexhalo.com/ai-crawlers/seznambot/
<a href="https://www.indexhalo.com/ai-crawlers/seznambot/">SeznamBot block rate across major websites, IndexHalo</a>