🤖 Overview

CoolCheck is a legitimate web crawler operated by the website monitoring service CoolCheck.net, a company that provides uptime and performance monitoring for web properties. The bot’s sole purpose is to periodically fetch pages from monitored websites to verify availability, response time, and content integrity, feeding data into CoolCheck’s alerting dashboard. According to CoolCheck’s official documentation (https://coolcheck.net/bot), the crawler is explicitly designed to be non-intrusive and respects standard web crawling etiquette.

🌐 Technical Behavior

The CoolCheck bot performs HTTP GET requests from a fixed set of IP ranges published in CoolCheck’s public IP list (https://coolcheck.net/ips), typically within the 185.34.33.0/24 and 185.34.34.0/24 subnets. Requests are made every 1 to 5 minutes per monitored URL, with a configurable interval set by the site owner. The bot uses TLS 1.2 or 1.3 and sends a custom X-CoolCheck: true header alongside standard headers. It does not follow redirects beyond three hops to avoid infinite loops and does not crawl linked resources unless explicitly configured for deep monitoring. The crawler operates 24/7 but pauses automatically if it receives a 503 or 429 status code.

📋 robots.txt Compliance

CoolCheck fully respects the robots.txt file. According to their official policy (https://coolcheck.net/robots), the bot will not crawl any URL blocked by a Disallow directive, including wildcard patterns. If no robots.txt exists, the bot assumes full crawl permission but still obeys Crawl-Delay directives. This behavior is verified by independent webmaster forums and the bot’s published User-Agent string, which references CoolCheck/1.0.

🔍 Detection Indicators

The primary User-Agent string is Mozilla/5.0 (compatible; CoolCheck/1.0; +https://coolcheck.net/bot). A behavioral fingerprint is the mandatory X-CoolCheck: true HTTP header, which is unique to this bot. Additionally, the bot sends a Referer header set to https://coolcheck.net and uses a fixed IP range as listed above. The request rate is consistently low (never exceeding 1 request per 60 seconds per monitored domain).

📊 Data Usage

Data collected by the CoolCheck bot is used exclusively for uptime monitoring and response-time measurement. The bot stores the HTTP status code, response time in milliseconds, and the full HTML body (for content-change detection) for a maximum of 30 days. This data is presented in the CoolCheck control panel and is never shared with third parties or used for AI training, as confirmed in CoolCheck’s privacy policy (https://coolcheck.net/privacy).

⚙️ Rate Limiting Policy

Rate limiting is applied because even legitimate monitoring bots can inadvertently cause load spikes on small servers; CoolCheck advises administrators to set a threshold of 10 requests per minute per IP before blocking, as the bot will automatically back off and respect the 429 response. This policy is documented in their rate-limiting FAQ at https://coolcheck.net/rate-limiting.

ⓘ 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.