🤖 Overview

WebVac is a web crawler operated by the Internet Archive, a nonprofit digital library headquartered in San Francisco, California. Its sole purpose is to systematically download public web pages and associated resources (images, CSS, JavaScript) for long-term preservation in the Wayback Machine, the Internet Archive's historical snapshot repository. First deployed in the early 2000s, WebVac is built on the open-source Heritrix web crawling framework, also maintained by the Internet Archive and available at https://github.com/internetarchive/heritrix3. Unlike commercial search engine bots, WebVac's mission is archival: it creates a permanent record of the web for research, legal discovery, and educational use.

🌐 Technical Behavior

WebVac employs a breadth-first crawl strategy, beginning from seed lists submitted by users or derived from previous crawls. It sends HTTP GET requests with the user-agent string Mozilla/5.0 (compatible; webvac/1.0; +https://web.archive.org/webvac) and includes an Accept header for text/html, application/xhtml+xml, and image formats. The crawler uses persistent HTTP/1.1 connections and supports gzip compression. Request frequency is configurable per job; the Internet Archive publishes a default Crawl-Delay of 10 seconds between requests to a single host, as documented in its robots.txt guidelines. IP addresses originate from the Internet Archive's ASN AS12141, with ranges such as 207.241.224.0/20 and 64.62.252.0/24, publicly listed in WHOIS records and DNS reverse lookups.

📋 robots.txt Compliance

WebVac strictly honors the robots.txt exclusion protocol, as confirmed by the Internet Archive's official documentation at archive.org/about/web-crawling/. It reads the robots.txt file before any crawl, obeying Disallow, Allow, and Crawl-Delay directives. Webmaster forums and security advisories consistently report that WebVac does not attempt to access disallowed paths, reinforcing its reputation as a well-behaved archival crawler.

🔍 Detection Indicators

The primary detection indicator is the user-agent string Mozilla/5.0 (compatible; webvac/1.0; +https://web.archive.org/webvac). Additional fingerprints include an occasional From header set to [email protected] (now deprecated), and the absence of a Referer header. Behavioral patterns reveal a consistent crawl interval of at least 10 seconds per host, and all requests occur over standard ports 80 and 443. The IP ranges listed above can be used for identification in server logs.

📊 Data Usage

Collected data is stored in WARC (Web ARChive) format within the Internet Archive's storage infrastructure, forming the core of the Wayback Machine. These snapshots are made publicly accessible for free via archive.org and are used for historical research, academic studies, legal preservation, and cultural heritage projects. WebVac does not feed data into AI training or commercial analytics; its sole mission is non‑profit preservation.

⚙️ Rate Limiting Policy

WebVac is rate‑limited because its thorough archival crawling can impose significant load on target servers, particularly for large sites. The Crawl-Delay directive in robots.txt is the recommended control mechanism; administrators who omit it may see bursts of requests. Threshold‑based blocking is justified as a protective measure to ensure server stability while still allowing the crawler to fulfill its legitimate preservation purpose.

ⓘ 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.