🤖 Overview

crawler@ is a user‑agent string observed in web server logs that is associated with a variety of legitimate automated agents, including custom search‑engine indexers, SEO audit tools, and academic research crawlers. Unlike major commercial bots such as Googlebot or Bingbot, crawler@ does not belong to a single known operator; rather, it is a generic pattern used by many independent scripts and small‑scale crawlers. Its purpose is typically to collect publicly accessible web content for indexing, competitive analysis, or data mining, though no single product or company is officially linked to this exact user‑agent.

🌐 Technical Behavior

crawler@ bots generally send HTTP GET requests with moderate frequency, often between 1 and 5 requests per second per IP. They commonly originate from cloud hosting providers such as AWS, DigitalOcean, and Google Cloud Platform, with IPv4 and IPv6 addresses. The bot tends to request paths like /robots.txt, /sitemap.xml, and then follow internal links sequentially. Some instances exhibit a referrer header pointing to the operator’s website, while others omit it entirely. The user‑agent string varies: a typical example is "Mozilla/5.0 (compatible; crawler@; +http://example.com)" but many versions exist without a valid contact URL.

📋 robots.txt Compliance

Based on analysis of public web logs and operator documentation (where available), most crawler@ instances honor robots.txt directives, particularly Disallow and Crawl‑Delay. However, because the agent is not centrally managed, compliance can be inconsistent. Some poorly‑configured crawlers ignore Disallow or fail to respect Crawl‑Delay values, leading to aggressive crawling patterns. The official guidance from major webmaster forums recommends setting Crawl‑Delay to at least 10 seconds to limit impact.

🔍 Detection Indicators

Primary detection is through the User‑Agent string containing "crawler@" or variations like "crawler@ (compatible;)". Additional indicators include a low Accept‑Language header (often "en‑US,en;q=0.5") and occasional absence of Accept‑Encoding. Behavioral fingerprints include rapid successive requests to the same domain, often without a referrer. The IP addresses frequently resolve to hosting providers in the same /24 block over a short period. Some instances send a From header containing an email address matching the user‑agent pattern.

📊 Data Usage

Data collected by crawler@ agents is used for a range of legitimate purposes, including search engine indexing (typically for niche or private search engines), SEO monitoring, price comparison, academic research, and web analytics. Operators may aggregate content for market intelligence or training small‑scale machine‑learning models. Because the bot is unaffiliated with a major platform, data usage policies vary widely and are rarely publicly documented.

⚙️ Rate Limiting Policy

Web administrators should rate‑limit crawler@ to prevent excessive server load, as its unbounded request rate can degrade performance for other visitors. A threshold of 5 requests per second per IP with a 429 Too Many Requests response after exceeding the limit is a recommended policy, balancing legitimate access with resource protection.

ⓘ 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.