🤖 Overview

The research robot is a web crawler operated by the Common Crawl Foundation, a non-profit organization that maintains a free, open repository of web crawl data. Its primary purpose is to collect publicly accessible web pages for academic research, AI training, and natural language processing projects. The data it gathers feeds into the Common Crawl dataset, which is widely used by universities, startups, and large language model developers such as OpenAI, Google, and Meta. First deployed in 2008, the crawler has evolved to support both broad and focused crawling campaigns. The robot’s operations are transparently documented on the Common Crawl website, including crawl logs and archive indexes.

🌐 Technical Behavior

The research robot employs a distributed crawling architecture, typically running many parallel threads across multiple IP addresses belonging to the Amazon Web Services (AWS) and Google Cloud Platform ranges. It uses HTTP/1.1 and HTTP/2 protocols and respects robots.txt directives. The crawler downloads pages at a rate of approximately 20–50 requests per second per host, though it can be more aggressive when crawling large websites. It follows no-follow and canonical tags, but does not execute JavaScript or render dynamic content. The crawler’s behavior is described in the official Common Crawl documentation at commoncrawl.org and in their GitHub repository (github.com/commoncrawl). It prioritizes text extraction and respects Content-Length limits, typically discarding pages over 10 MB.

📋 robots.txt Compliance

The research robot fully adheres to the Robots Exclusion Standard. According to Common Crawl’s published policy, the crawler will not index any path or file that is disallowed in robots.txt. It also respects Crawl-Delay directives set by webmasters. Evidence from Common Crawl’s own documentation confirms that they monitor compliance and have scripts to re-fetch robots.txt periodically during a crawl. However, the crawler does not respond to X-Robots-Tag headers or noindex meta tags in HTML, as it does not parse page-level metadata beyond basic robots meta tags in the HTML .

🔍 Detection Indicators

The research robot identifies itself with the User-Agent string Mozilla/5.0 (compatible; research robot; +https://commoncrawl.org/bot) and also uses variants such as CommonCrawl/1.0 or CCBot/2.0. The bot typically sends a User-Agent header and a From header containing the Common Crawl contact email ([email protected]). Its IP ranges are publicly listed in the Common Crawl IP ranges file, which includes AWS and GCP blocks. Behavioral fingerprints include high concurrency, consistent request intervals, and a tendency to fetch robots.txt before any other page on a domain.

📊 Data Usage

The collected data is stored as compressed WARC files and made freely available for academic research, AI training, search indexing experiments, and linguistic analysis. The Common Crawl dataset is used to train models like BERT, GPT-3, and LLaMA. According to the Common Crawl Foundation, the data is also used for web graph analysis, spam detection research, and historical archiving. No personally identifiable information (PII) is intentionally retained, and the dataset undergoes periodic filtering to remove sensitive content.

⚙️ Rate Limiting Policy

Despite its legitimate status, the research robot is commonly rate-limited because its high volume and parallelism can overload servers not prepared for sustained crawling. Web administrators are advised to set a Crawl-Delay of 10–30 seconds and apply IP-based throttling using tools like nginx or fail2ban to protect backend resources while still allowing the bot to index valuable research data.

ⓘ 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.