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Identifying & managing bots

Crawler IP ranges

Crawler IP ranges are the IP address blocks from which a search engine operator runs its crawlers. Google publishes them as JSON files in CIDR format. To check whether a request really came from Googlebot, you compare the IP address in your log with these lists.

Which lists exist?

Google splits the ranges by crawler group. The verification documentation lists these files under developers.google.com/static/crawling/ipranges/:

  • common-crawlers.json for common crawlers such as Googlebot
  • special-crawlers.json for crawlers with a special purpose such as AdsBot
  • user-triggered-fetchers.json and user-triggered-fetchers-google.json for fetches that a user starts
  • user-triggered-agents.json for user-triggered agents
Is it really Googlebot?Five-step flow: take the IP address from the log file, run a reverse DNS lookup, check that the hostname ends in googlebot.com, google.com or googleusercontent.com, run a forward DNS lookup on that hostname, check that the same IP comes back. Only if both checks pass does the request come from Google. Alternatively, the IP is matched against the JSON lists Google publishes.1 · IP address from the log file66.249.66.12 · Reverse DNS lookupcrawl-66-249-66-1.googlebot.com3 · Hostname ends ingooglebot.com, google.com, googleusercontent.com?yes4 · Forward DNS lookup on the hostname66.249.66.15 · Same IP as in the log file?yesRequest comes from Googlenonot Googlenonot GoogleOr automaticallyMatch the IP against Google’sJSON lists (CIDR format):common-crawlers.jsonspecial-crawlers.jsonuser-triggered-fetchers.jsonuser-triggered-fetchers-google.jsonuser-triggered-agents.jsonOther crawlers often spoofthe Googlebot user agent.It proves nothing on its own.
Both DNS lookups have to match. For large-scale lookups, Google recommends matching against its published IP lists automatically. Sample values from Google’s documentation. Sources: Google Crawling: Verify requests from Google crawlers and fetchers; Google Search Central: What is Googlebot.

The 2026 move

On March 31, 2026, Google announced that the files move from /search/apis/ipranges/ to /crawling/ipranges/, because the ranges apply to more than Search crawlers. The old paths were to stay available for a while and redirect to the new ones within six months. On October 6, 2026, the old googlebot.json answered with a 301 redirect to common-crawlers.json. Scripts that fetch the files should use the new paths and follow redirects.

Format

The files contain a creation timestamp and a list of IPv4 and IPv6 prefixes. Ranges change, so a downloaded copy ages. The timestamp shows how current your copy is. The IP addresses in a log file can be personal data (CJEU, judgment of October 19, 2016, C-582/14, Breyer). This is not legal advice.

Example

A shortened file in the documented structure (placeholder values from the documentation address range):

JSON
{
  "creationTime": "2026-10-06T14:47:46.000000",
  "prefixes": [
    {"ipv6Prefix": "2001:db8::/32"},
    {"ipv4Prefix": "192.0.2.0/24"}
  ]
}

If the IP address of a request falls inside one of the prefixes, the request comes from Google’s infrastructure.

Common mistakes

  • Using lists of single IP addresses copied from blog posts or forum answers. They do not show which crawler group an address belongs to and are not updated.
  • Allowlisting a downloaded copy once and never refreshing it.
  • Treating every IP from a user-triggered list like Googlebot. Google states that user-triggered fetchers generally ignore robots.txt.
  • Matching only common-crawlers.json. AdsBot and other special-purpose crawlers are listed in special-crawlers.json.
  • Matching only IPv4 prefixes. The files contain both ipv4Prefix and ipv6Prefix entries.

Alternative to the lists

Google also describes a manual check. A reverse DNS lookup must return a name ending in googlebot.com, google.com or googleusercontent.com, and a forward lookup of that name must return the original IP.

FAQ

What are Google’s IP ranges? The prefixes in the JSON files above. They are the lists Google documents for verifying its crawlers.

How do I identify a Google crawler? Match the IP against the ranges or use reverse and forward DNS.

Sources

  1. Verifying Google crawlers and fetchers – Google Crawling Infrastructuredevelopers.google.com
  2. New location for the Google crawlers' IP range files – Google Search Central Blog (Mar 31, 2026)developers.google.com
  3. Google user-triggered fetchers – Google Search Centraldevelopers.google.com
  4. common-crawlers.json – Google (file checked 2026-10-06)developers.google.com
  5. Update your Google crawler IP range endpoints – Merj (secondary)merj.com
  6. Judgment of the CJEU of 19 October 2016, C-582/14 (Breyer)eur-lex.europa.eu

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