Baiduspider Pattern Reference Checker

Read the result as a pattern match

This checker gives you three separate clues about a suspected Baiduspider request. In User-Agent mode, paste the header text to see whether it contains the word Baiduspider, which recognized subtype pattern appears, any version-like number, and a help URL included in the text. In IP mode, enter an IPv4 or IPv6 address to check its format and compare IPv4 addresses with eight embedded historical network ranges. A range match means only that the address falls inside one of those references.

For a stronger check, IP mode also offers an explicit reverse-and-forward DNS lookup. It checks whether a reverse lookup returns a hostname beneath baidu.com or baidu.jp, then whether a forward lookup of that hostname returns the entered IP. Baidu’s guidance describes this two-way check against the source address in your server logs and says its crawler IP pool changes, so a fixed complete IP list is not available. The embedded ranges have unverified sources and dates; they are not Baidu’s official list. Baidu’s crawler identification guidance explains why a static range comparison is not enough.

These outputs answer different questions: a User-Agent match detects a claim in text, a range match compares an address with a local reference, and a successful DNS result checks the two DNS conditions for that address at lookup time. Only the DNS lookup uses DNS; the other two are pattern comparisons. None of these checks authenticates every part of an HTTP request or establishes that a request is safe.

Check a log entry in the right order

1. Start with the recorded request

   Use the User-Agent string and source IP from a trusted server or edge log. A browser’s own User-Agent can be loaded as an example, but it does not represent a Baiduspider visit to your site.

2. Inspect the User-Agent text

   Choose User-Agent Identification and paste the complete value. The result can flag the main Baiduspider token or patterns such as image, video, news, mobile/render, favorites, alliance, and ads. It may also show a version, mobile indicators, and a URL written into the string. Treat all of these as text clues because a sender can copy or invent them.

3. Compare an IP, then request DNS verification

   Choose IP Range Lookup and enter a literal IP address; hostnames are not accepted. A valid IPv4 may show one matching embedded range or no range match. IPv6 can be submitted for the DNS check, but it cannot match the IPv4 reference ranges. Select “Verify reverse + forward DNS” when you want the additional check. It is an explicit lookup, not an automatic result of entering an IP.

4. Interpret the DNS status

   “Verified” means a returned hostname met the Baidu suffix rule and a forward lookup returned the entered address. “Does not pass” means the available DNS result did not satisfy that rule. “Unknown” means DNS could not establish a conclusion, such as when lookups fail. Keep the source IP and timestamp with the log evidence when reviewing the event.

Questions about Baiduspider checks

Keep identity checks separate from access rules

Use an IP taken from a trusted request log, not an arbitrary address or an untrusted forwarded header. The DNS action makes DNS queries for the supplied address; it does not connect to that address. A successful result applies to the checked IP and DNS responses at that time, not to the integrity of the whole request. A failed or unavailable lookup can reflect DNS conditions and should not automatically be treated as proof of impersonation.

Do not use the embedded historical ranges or a User-Agent match alone to create firewall allowlists, block rules, or access permissions. Baidu notes that its crawler IP pool changes and recommends checking actual request IPs through DNS rather than relying on a fixed complete range list. Review your logs and operational context before taking action.