Create a link health checker

Creating a link health checker involves building a tool that can scan a list of URLs and verify whether those links are working (returning valid HTTP responses) or broken (returning errors or no response). Here’s a simple example of how to build one in Python, which can be easily adapted for web or command-line use.

python
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import requests

def check_link_health(urls, timeout=5):
    """
    Check the health of a list of URLs.

    Args:
        urls (list): List of URL strings to check.
        timeout (int): Timeout for each request in seconds.

    Returns:
        dict: Dictionary with URL as key and status as value.
    """
    results = {}
    headers = {
        'User-Agent': 'LinkHealthChecker/1.0'
    }

    for url in urls:
        try:
            response = requests.head(url, timeout=timeout, headers=headers, allow_redirects=True)
            # If HEAD is not allowed, fall back to GET
            if response.status_code >= 400 or response.status_code == 405:
                response = requests.get(url, timeout=timeout, headers=headers, allow_redirects=True)

            status_code = response.status_code

            if 200 <= status_code < 400:
                results[url] = f"Healthy (Status code: {status_code})"
            else:
                results[url] = f"Broken (Status code: {status_code})"

        except requests.exceptions.RequestException as e:
            results[url] = f"Error ({e})"

    return results

# Example usage:
if __name__ == "__main__":
    urls_to_check = [
        "https://www.google.com",
        "https://www.example.com/nonexistentpage",
        "https://thiswebsitedoesnotexist12345.com"
    ]

    health_report = check_link_health(urls_to_check)
    for url, status in health_report.items():
        print(f"{url}: {status}")

Explanation:

• The script uses requests.head() first for faster checks.

• If HEAD is disallowed or returns error, falls back to GET.

• Handles redirects with allow_redirects=True.

• Considers HTTP status codes in 200–399 range as healthy.

• Catches exceptions (timeout, DNS failures, etc.) and reports errors.

• Easily expandable to read URLs from files or databases.

If you want, I can also provide a version in JavaScript (Node.js) or a simple front-end implementation!