🤖 Overview

webimages is a web crawler operated by Yahoo! as part of its Yahoo! Slurp spider system, specifically designed for discovering and indexing images across the internet to populate Yahoo! Image Search results. This bot, commonly identified with the user-agent string Yahoo! Slurp [webimages], focuses on fetching image files and analyzing their metadata for search relevance.

🌐 Technical Behavior

The webimages crawler follows link structures to locate images, using HTTP requests to retrieve files with common extensions such as .jpg, .png, .gif, and .webp. It operates from IP addresses owned by Yahoo! (now part of Verizon Media and later Apollo Global Management), typically within netblocks such as 74.6.0.0/16, 98.136.0.0/16, and 66.216.0.0/16, as documented in public WHOIS records. The crawler uses GET and HEAD requests, respects Last-Modified and ETag headers to minimize redundant downloads, and employs exponential backoff when encountering server errors or rate-limiting responses. Its crawl frequency can be high on sites with many images, sometimes making several requests per second, but it respects the Crawl-Delay directive in robots.txt.

📋 robots.txt Compliance

Yahoo! Slurp (including the webimages variant) is documented to honor both Disallow and Allow directives in robots.txt files, as per Yahoo’s official crawler guidelines published at help.yahoo.com. The bot will not access URLs or directories explicitly forbidden, and it reads the robots.txt file at least once per 24 hours, caching the rules. Evidence from Yahoo’s help pages confirms that webimages respects the Crawl-Delay instruction to throttle its request rate.

🔍 Detection Indicators

The primary user-agent string is Mozilla/5.0 (compatible; Yahoo! Slurp; http://help.yahoo.com/help/us/ysearch/slurp) with an additional identifier [webimages] appended for image-specific crawling. Alternative strings include Yahoo! Slurp [webimages] and Yahoo! Slurp (webimages). IP addresses reverse-DNS resolve to hosts such as slurp.yahoo.com or yimg.com. The crawler sends a standard User-Agent header and does not spoof other identities.

📊 Data Usage

The collected image data, including URLs, file sizes, dimensions, alt text, and surrounding page context, is used exclusively to build and update Yahoo’s image search index, providing users with relevant image results for search queries. The crawler does not repurpose images for AI training or other products, as per Yahoo’s privacy policy. The data is stored on Yahoo’s servers and is subject to their data retention and usage terms.

⚙️ Rate Limiting Policy

Due to potentially high request volume from webimages, especially on media-rich websites, administrators are advised to implement rate limiting thresholds (e.g., 10 requests per second per IP) to prevent resource exhaustion. Yahoo’s own guidance recommends using Crawl-Delay in robots.txt, but if the bot does not comply, temporary IP blocking is justified as a protective measure for server stability.

ⓘ 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.