🤖 Overview

CCBot is the web crawler operated by the non-profit organization Common Crawl Foundation, based in Redwood City, California. Its primary mission is to maintain an open, publicly accessible repository of web crawl data—currently over 3.8 billion pages per month—that is provided free of charge for research, academic study, and the training of large language models and other AI systems. Unlike commercial search engine bots, Common Crawl does not operate a public search engine; the collected corpus is used directly by organizations such as OpenAI, Google, Amazon, and numerous universities to build and refine natural language processing models. The project began in 2007 with the file system (arc files) and was formally launched as Common Crawl in 2011. Crawls are performed roughly every month, with the latest data available via Amazon S3 and the Common Crawl website (commoncrawl.org).

🌐 Technical Behavior

CCBot employs a distributed crawling infrastructure running on Amazon EC2 instances, using open-source tools such as AWS Batch and Apache Nutch. The crawler fetches pages using HTTP/1.1 and HTTP/2, with a default request rate of 1 request per 1–2 seconds per IP, though the aggregate fleet can generate thousands of simultaneous connections across many IP addresses. The crawler's IP ranges are published in the Common Crawl FAQ and include subnets such as 54.236.1.0/24 and 184.73.0.0/16 (AWS EC2 regions us-east-1 and us-west-2). CCBot respects the If-Modified-Since header for incremental crawls and uses ETags where available. The crawler’s behavior is documented in the official Common Crawl FAQ (commoncrawl.org/faq/), which details that it does not follow JavaScript redirects or execute JavaScript by default.

📋 robots.txt Compliance

According to Common Crawl’s official documentation (commoncrawl.org/faq/#do-you-obey-robots-txt), CCBot fully respects the Robots Exclusion Protocol (robots.txt). The crawler checks the /robots.txt file for the first request to each host and caches the rules for the duration of the crawl. Webmasters can block CCBot by adding User-agent: CCBot followed by Disallow: / in their robots.txt file. Common Crawl also provides a dedicated opt-out form for websites that cannot modify robots.txt, as listed on their “Opt-Out” page. There are no documented cases of CCBot ignoring robots.txt directives.

🔍 Detection Indicators

The primary identifier is the User-Agent string: CCBot/2.0 (https://commoncrawl.org/faq/) for the current version (as of mid-2024). Earlier versions included CCBot/1.0. The bot also sends a From header reading [email protected] in some configurations. The IP addresses are consistently from Amazon EC2 (AS16509, AS14618), and the bot’s reverse DNS often resolves to ec2-*-*-*-*.compute-1.amazonaws.com. The request pattern is highly regular—each host is hit with approximately one request every 60–120 seconds, with no bursts, making it distinguishable from aggressive scrapers.

📊 Data Usage

All data collected by CCBot is stored in the Common Crawl Archive—a collection of WARC (Web ARChive) files hosted on Amazon S3. These files include raw HTML, metadata, and extracted text. The dataset is used for training large language models (e.g., GPT-3, LLaMA, Falcon), natural language processing benchmarks (e.g., C4, The Pile), and academic research in fields such as web science and computational linguistics. As of 2024, Common Crawl’s dataset has been downloaded over 300,000 times, according to their official usage statistics. The data is also used by companies like Google (informing some AI training) and by academic researchers to study web structure.

⚙️ Rate Limiting Policy

CCBot is rate-limited not because it is malicious, but to prevent overloading origin servers—its distributed fleet can produce a high aggregate request volume across millions of pages. Webmasters are encouraged to set rate-limiting thresholds (e.g., blocking if requests exceed 5 per second from a single IP) as a precautionary measure, as documented in the Common Crawl FAQ. The policy rationale is that the bot is designed to be polite but can still be aggressive on shared hosting environments.

ⓘ Data Notice: The information presented above has been compiled from publicly available internet sources. Boteraser aggregates this data solely for informational purposes and does not independently classify, evaluate, or endorse any findings about the bots listed. The accuracy and completeness of this information is the sole responsibility of the original publishers. Boteraser and its operators accept no liability for any decisions made based on this data.