Free HTTP External Link Checker & Web Crawler Tool

(async () => {
    console.log("%c🚀 Starting Link Analysis...", "color: #4f46e5; font-weight: bold; font-size: 14px;");
    
    // 1. Collect all anchor tags with absolute HTTP/HTTPS links
    const currentHost = window.location.host;
    const links = Array.from(document.querySelectorAll('a[href^="http"]'));
    
    // 2. Filter for unique external links
    const externalLinks = [];
    const seenUrls = new Set();

    links.forEach(link => {
        try {
            const url = new URL(link.href);
            if (url.host !== currentHost && !seenUrls.has(url.href)) {
                seenUrls.add(url.href);
                externalLinks.push({
                    anchorText: link.textContent.trim() || '[No Anchor Text]',
                    url: url.href
                });
            }
        } catch (e) {
            // Skip invalid URLs
        }
    });

    if (externalLinks.length === 0) {
        console.log("✅ No external links found on this page.");
        return;
    }

    console.log(`🔍 Found ${externalLinks.length} unique external links. Verifying status codes...`);
    console.table(externalLinks); // Show initial map

    // 3. Asynchronously test each link via fetch (HEAD request)
    const results = [];
    
    for (const item of externalLinks) {
        try {
            // Using HEAD request to optimize speed and bandwidth
            const response = await fetch(item.url, { 
                method: 'HEAD', 
                mode: 'no-cors' // Bypasses strict CORS block, but will return status 0 for protected sites
            });
            
            // Note: 'no-cors' forces an opaque response, meaning JS can't always view the exact status code (returns 0)
            // If it succeeds without throwing an error, the endpoint is generally reachable.
            results.push({
                "Anchor Text": item.anchorText,
                "External URL": item.url,
                "Status": response.status === 0 ? "OK (Opaque/Protected)" : response.status
            });
        } catch (error) {
            results.push({
                "Anchor Text": item.anchorText,
                "External URL": item.url,
                "Status": "FAILED / TIMEOUT"
            });
        }
    }

    // 4. Output beautiful responsive table directly in the console
    console.log("%c📊 Final Analysis Results:", "color: #10b981; font-weight: bold; font-size: 14px;");
    console.table(results);
})();