← All Status Codes
404
Not Found
⚠️ Client Error
Low Risk
📖 What Is HTTP 404?
The server cannot find the requested resource. This could be a temporary or permanent condition. The most commonly encountered error on the web.
🛡️ Security Implications
Attackers use 404 responses to enumerate valid paths, files, and directories. Custom 404 pages should not reveal server technology or internal paths.
🔍 Common Causes
Broken link, deleted page, typo in URL, missing file, incorrect permalink settings, or resource moved without a redirect.
🔧 How to Fix
Check URL spelling. Set up 301 redirects for moved content. Create a custom 404 page. Use tools to find and fix broken links.
🖥️ How to Check
curl -I -o /dev/null -w "%{http_code}" https://example.com