Caution Reported AI & LLM Bots

Yiyan Fetcher (Baidu)

Q: What user-agent string does Yiyan Fetcher (Baidu) use?

Yiyan Fetcher (Baidu) is reported to identify itself with YiyanBot . Evidence that the spelling is in real use comes from our own robots.txt study: 20 of the 5,583 valid robots.txt files in the Tranco top 10,000 name it (fetched October 20, 2026), not from Baidu, which has not published crawler documentation naming it. Use it in robots.txt as the best available match, and treat a request carrying it as a clue rather than proof of who sent it.

Q: Is Yiyan Fetcher (Baidu) safe?

Yiyan Fetcher (Baidu) is rated Caution in this directory. It is a Reported token: Baidu has not published documentation for it, so its purpose, crawl rate and robots.txt behaviour are not confirmed by the operator, and anyone can send the same user-agent string. Allow or block it on its stated purpose, and back the robots.txt rule with a firewall rule if the traffic matters to you.

Q: Will blocking Yiyan Fetcher (Baidu) hurt my SEO?

✅ No SEO Impact - Blocking Yiyan Fetcher (Baidu) does not affect your rankings in Google, Bing, or any other search engine. Yiyan Fetcher (Baidu) is an AI crawler, not a traditional search indexer. You can freely block it via User-agent / Disallow: / without any SEO penalty.

Q: How do I block Yiyan Fetcher (Baidu) in robots.txt?

Add the following lines to your /robots.txt file: User-agent: YiyanBot Disallow: / This instructs Yiyan Fetcher (Baidu) not to crawl any path on your site. To block only specific sections, replace / with the path (e.g., Disallow: /blog/ ).

Q: How do I verify if Yiyan Fetcher (Baidu) is crawling my site?

Search your access logs for YiyanBot (for example grep -i "YiyanBot" /var/log/nginx/access.log ). Because the operator publishes no IP ranges or reverse-DNS pattern, a match shows that something used the name, not that Baidu sent it.

Operated by Baidu

Scout's quick take

YiyanBot (Yiyan Fetcher (Baidu)) visits a page only when a person asks Baidu's assistant to open it. It is not a background crawler. This profile is built from reported sightings, not vendor documentation.

# Block only if you really mean to
User-agent: YiyanBot
Disallow: /

Audit my AI crawler access Build a full robots.txt

Quick Facts

User-Agent:: YiyanBot
Category:: AI & LLM Bots
Operator:: Baidu
Safety:: Use Caution
Blocking Impact:: Low - No SEO ranking impact
SEO Impact Score:: 2/10
Official docs:: None published by Baidu
Evidence:: Verified by AI Crawler Check: in 20 top-10k robots.txt files

Reported, not operator documented

Baidu has not published a crawler page that names YiyanBot. It is listed here on our own evidence. Verified by AI Crawler Check: 20 of the 5,583 valid robots.txt files in the Tranco top 10,000 carry a rule for YiyanBot, so site owners treat it as a real crawler name (how we measure this). That proves the spelling is in use, not who sends it. Reported Baidu Yiyan token. No vendor page.

What that means for you: the YiyanBot rule on this page is the best available spelling, but Baidu has made no statement of purpose, crawl rate or robots.txt compliance. Treat a YiyanBot request in your logs as a clue, not proof of who sent it, and add a firewall rule if that traffic matters to you. If the operator publishes documentation, this profile moves to Official docs.

What is Yiyan Fetcher (Baidu)?

Yiyan Fetcher (Baidu) is an on-demand AI fetcher operated by Baidu. It retrieves a page only when a user explicitly asks an AI assistant or agent to read, summarize, or act on a specific URL. Because it is triggered by real user intent rather than bulk crawling, blocking it mainly prevents users from pulling your content into Baidu's assistant.
Yiyan Fetcher (Baidu) uses the user-agent token YiyanBot. You can control it via robots.txt, meta tags (noai), or the emerging llms.txt standard. Robots.txt is voluntary; for hard enforcement, combine it with server-level IP blocking.

What happens if you block Yiyan Fetcher (Baidu)?

✅ No SEO Impact - Blocking Yiyan Fetcher (Baidu) does not affect your rankings in Google, Bing, or any other search engine. Yiyan Fetcher (Baidu) is an AI crawler, not a traditional search indexer. You can freely block it via User-agent / Disallow: / without any SEO penalty.

Generally safe to allow; provides legitimate crawling value.

Want to see whether Yiyan Fetcher (Baidu) actually visits you? Read how do I monitor AI bot traffic to my website?

How to block Yiyan Fetcher (Baidu) with robots.txt

<code>User-agent: YiyanBot</code> - Matching is case-insensitive. Robots.txt is fetched from the root of each subdomain separately.

Block completely (robots.txt)

User-agent: YiyanBot
Disallow: /

Allow all (robots.txt)

User-agent: YiyanBot
Allow: /

Block private only (robots.txt)

User-agent: YiyanBot
Disallow: /private/
Disallow: /api/
Disallow: /admin/
Allow: /

Nginx server block

# Nginx: Hard-block Yiyan Fetcher (Baidu)
if ($http_user_agent ~* "YiyanBot") {
    return 403 "Bot blocked";
}

Apache .htaccess

# Apache: Hard-block Yiyan Fetcher (Baidu)
SetEnvIfNoCase User-Agent "YiyanBot" bad_bot
Order Allow,Deny
Allow from all
Deny from env=bad_bot

Meta robots tag

X-Robots-Tag header

X-Robots-Tag: noindex, nofollow

Is Yiyan Fetcher (Baidu) safe to allow?

Yiyan Fetcher (Baidu) is rated Caution in this directory. It is a Reported token: Baidu has not published documentation for it, so its purpose, crawl rate and robots.txt behaviour are not confirmed by the operator, and anyone can send the same user-agent string. Allow or block it on its stated purpose, and back the robots.txt rule with a firewall rule if the traffic matters to you.

Baidu publishes no IP ranges or reverse-DNS pattern for Yiyan Fetcher (Baidu), so the user-agent string cannot be verified. Rate-limit unusual volume instead of trusting the name.

What does Yiyan Fetcher (Baidu) do?

Understanding Yiyan Fetcher (Baidu)'s purpose helps you decide whether to allow or block it.

Fetches a page only when a user asks an AI assistant to read it
Summarizes or extracts the URL the user provided
Triggered by real user intent, not bulk crawling
Low traffic volume compared with training crawlers
Blocking it prevents users from pulling your content into the assistant

Yiyan Fetcher (Baidu) in context

Yiyan Fetcher (Baidu) is a user-triggered agent operated by Baidu. In plain terms, it fetches a page when a person asks an assistant or app to open it. Our database files it under AI and LLM crawlers and ranks it Tier 2, important crawlers from established AI and search operators. 74 of the 104 AI and LLM crawlers in our database share this tier.

Its safety rating is caution and its blocking impact is low. So the decision about Yiyan Fetcher (Baidu) rests on what you want from Baidu, not on its behaviour. How we rate safety and impact.

How site owners treat Yiyan Fetcher (Baidu)

In our own scan of the Tranco top 10,000 (5,583 valid robots.txt files), 20 files (0.4%) name YiyanBot in a User-agent line. That shows site owners treat the token as a real crawler worth a rule. It does not, on its own, prove who operates it.

Does it follow robots.txt?

Yiyan Fetcher (Baidu)'s operator does not clearly document how it treats robots.txt. Write the Yiyan Fetcher (Baidu) rule anyway, then confirm in your logs that its requests stop.

Baidu crawlers and close alternatives

Yiyan Fetcher (Baidu) is one of 10 Baidu crawlers in our database. A User-agent: YiyanBot group controls Yiyan Fetcher (Baidu) only; the other Baidu tokens below need their own lines.

YiyanBot: this crawler (Tier 2)
baidu: baidu, builds a search or answer index (Tier 3)
Baiduspider: Baidu Search, builds a search or answer index (Tier 3)
Baiduspider-ads: Baidu Business Search, checks pages for an SEO, uptime or analytics service (Tier 3)
Baiduspider-cpro: Baidu Union, checks pages for an SEO, uptime or analytics service (Tier 3)
Baiduspider-favo: Baidu Bookmark, builds a search or answer index (Tier 3)
Baiduspider-image: Baidu Image Search, builds a search or answer index (Tier 3)
Baiduspider-news: Baidu News Search, builds a search or answer index (Tier 3)
Baiduspider-video: Baidu Video Search, builds a search or answer index (Tier 3)

To give Yiyan Fetcher (Baidu) the same answer as its siblings, stack User-agent: YiyanBot with their lines above one set of rules; to treat Yiyan Fetcher (Baidu) differently, give it its own group.

Other AI and LLM crawlers that do the same job (fetches a page when a person asks an assistant or app to open it) include ChatGPT Agent from OpenAI, ChatGPT Operator from OpenAI, ChatGPT-User from OpenAI, ChatGPT-User/2.0 from OpenAI, Claude-SearchBot from Anthropic, Claude-User from Anthropic. Deciding about Yiyan Fetcher (Baidu) is usually a decision about the whole group, so check how your file treats these too.

We first recorded YiyanBot on September 22, 2026. We could not find a page where Baidu names it, so treat the token as reported rather than documented.

Which rule Yiyan Fetcher (Baidu) actually follows

Yiyan Fetcher (Baidu) reads exactly one group in robots.txt, the most specific one that names YiyanBot, and never combines rules across groups. This short file shows the trap:

User-agent: *
Disallow: /private/

User-agent: YiyanBot
Disallow: /drafts/

Find the group. Yiyan Fetcher (Baidu) looks for a group naming YiyanBot. One exists, so it ignores User-agent: * completely.
Apply only that group. It is refused /drafts/ and nothing else.
The surprise. /private/ is open to Yiyan Fetcher (Baidu), because that rule lives in the * group it no longer reads. To keep it out of both, repeat Disallow: /private/ inside its own group.

Test yourself: does a rule under User-agent: * apply to Yiyan Fetcher (Baidu) if the file also has a User-agent: YiyanBot group?

No. Once a group names it, Yiyan Fetcher (Baidu) reads only that group. Put every rule you want it to follow inside its own group.

Test yourself: will blocking Yiyan Fetcher (Baidu) remove your pages from AI answers?

Often, yes. Yiyan Fetcher (Baidu) is a user-triggered agent, so pages it cannot fetch can drop out of the answers or results it supports.

Test yourself: is User-agent: yiyanbot the same as User-agent: YiyanBot?

Yes. RFC 9309 makes user-agent matching case-insensitive. Paths are a different story: Disallow: /Blog/ does not block /blog/.

Should you allow Yiyan Fetcher (Baidu)? Decide by situation

Recommended setting for Yiyan Fetcher (Baidu) by type of site
If you are...	Recommended setting
You publish content and want AI answers to cite it	Allow it. Yiyan Fetcher (Baidu) fetches pages for answers, so blocking it can remove you from them.
You license content and want to stop AI training	Blocking it does not stop training, because Yiyan Fetcher (Baidu) is a user-triggered agent. Block the operator's training crawler instead.
You run an online shop	Allow it on product and category pages, which are the pages shoppers ask assistants about.
Your server is under load from bots	Rate-limit before blocking. It is rated caution in our database.

Check Yiyan Fetcher (Baidu) on your own site

Open /robots.txt on your domain and search for YiyanBot. If it is not named, it follows User-agent: *.
List the Disallow lines in the group Yiyan Fetcher (Baidu) follows and test your key URLs against them; the longest match wins, and Allow wins a tie.
Look beyond the file. A firewall or bot manager can refuse Yiyan Fetcher (Baidu) even when robots.txt allows it, and that never shows in the file.
Run our AI crawlability checker to see how Yiyan Fetcher (Baidu) and every other crawler we track are treated in one pass, including firewall refusals.

Common mistakes with Yiyan Fetcher (Baidu)

The errors we see most often with Yiyan Fetcher (Baidu) in the files and firewalls we test:

Assuming a robots.txt rule will stop Yiyan Fetcher (Baidu). User-triggered fetches act for a person, and some operators say robots.txt may not apply to them. Check the operator's statement above.
Blocking Yiyan Fetcher (Baidu) as if it were a bulk crawler. It fetches one page because a person asked; blocking it means that person's assistant cannot read your page.
Counting Yiyan Fetcher (Baidu) visits as crawl volume. Each request maps to a real user question, which makes the paths it requests a useful signal of what people ask about you.

All three hide inside a file that looks correct, so check Yiyan Fetcher (Baidu) from outside after every change.

Spotting Yiyan Fetcher (Baidu) in your logs

robots.txt says what Yiyan Fetcher (Baidu) may do; your access logs show what it actually did.

Count requests

On a server with standard Nginx or Apache logs, this counts matching requests per day (adjust the log path for your host):

grep -iE "YiyanBot" /var/log/nginx/access.log \
  | awk '{print $4}' | cut -d: -f1 | sort | uniq -c

And this shows which paths it requested most, which is the quickest way to see whether your Disallow lines are being respected:

grep -iE "YiyanBot" /var/log/nginx/access.log \
  | awk '{print $7}' | sort | uniq -c | sort -rn | head -20

Check the requests are genuine

Anyone can send the Yiyan Fetcher (Baidu) user-agent, so confirm the source before acting on a match:

YiyanBot: we hold no published IP list, so use reverse DNS where the operator documents a hostname and treat an unverifiable Yiyan Fetcher (Baidu) request with caution.

Frequently Asked Questions

What user-agent string does Yiyan Fetcher (Baidu) use?

Yiyan Fetcher (Baidu) is reported to identify itself with YiyanBot. Evidence that the spelling is in real use comes from our own robots.txt study: 20 of the 5,583 valid robots.txt files in the Tranco top 10,000 name it (fetched October 20, 2026), not from Baidu, which has not published crawler documentation naming it. Use it in robots.txt as the best available match, and treat a request carrying it as a clue rather than proof of who sent it.

Is Yiyan Fetcher (Baidu) safe?

Will blocking Yiyan Fetcher (Baidu) hurt my SEO?

How do I block Yiyan Fetcher (Baidu) in robots.txt?

Add the following lines to your /robots.txt file:

User-agent: YiyanBot
Disallow: /

This instructs Yiyan Fetcher (Baidu) not to crawl any path on your site. To block only specific sections, replace / with the path (e.g., Disallow: /blog/).

Does Yiyan Fetcher (Baidu) respect robots.txt?

Not documented. Baidu has published no statement that Yiyan Fetcher (Baidu) reads robots.txt. A rule for YiyanBot will stop a client that chooses to honour it; for enforcement, add a firewall or CDN rule as well.

How do I verify if Yiyan Fetcher (Baidu) is crawling my site?

Search your access logs for YiyanBot (for example grep -i "YiyanBot" /var/log/nginx/access.log). Because the operator publishes no IP ranges or reverse-DNS pattern, a match shows that something used the name, not that Baidu sent it.