HTTP Status Code & Security Headers Inspector

Look up definitions, causes, and troubleshooting fixes for HTTP 1xx, 2xx, 3xx, 4xx, and 5xx status codes with security header guides.

Category: URL & Internet

How to Use HTTP Status Code & Security Headers Inspector

Select any HTTP status code from the categorized dropdown menu (1xx to 5xx).
Click Inspect Status or Execute to view the official RFC 9110 definition, technical meaning, and triggers.
Review recommended developer solutions, server-side troubleshooting steps, and caching rules.
Consult the included HTTP security headers checklist to harden web server response headers.

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Frequently Asked Questions

Is this tool a live remote HTTP probe or an educational reference inspector?

This tool is an educational reference guide and security headers inspector based on official IETF RFC standards. Because browser-based JavaScript cannot arbitrarily probe remote servers across origins without being blocked by CORS (Cross-Origin Resource Sharing) or triggering SSRF (Server-Side Request Forgery) security risks, EverySolve provides verified RFC definitions, root causes, and security header configurations locally without making unauthenticated network calls.

What is the difference between a 301 Moved Permanently and a 302 Found redirect?

A 301 redirect indicates that the requested resource has been permanently moved to a new URI, instructing search engines to transfer ranking signals (link equity) to the target URL and telling browsers to cache the redirect. A 302 redirect indicates a temporary move, instructing search engines to retain the original URL in their index and preventing browsers from caching the redirection permanently.

What are the most common causes of 500 Internal Server Error and 502 Bad Gateway responses?

A 500 Internal Server Error is a catch-all server-side error typically caused by unhandled application exceptions, database connection timeouts, syntax errors in backend scripts, or misconfigured web server directives (.htaccess or nginx.conf). A 502 Bad Gateway error occurs in reverse proxy setups (e.g., Cloudflare or Nginx fronting a Node.js/PHP backend) when the proxy server receives an invalid or empty response from the upstream application server.

Which essential HTTP security headers should every modern production website implement?

Production web servers should declare: 1) Content-Security-Policy (CSP) to mitigate Cross-Site Scripting (XSS) and data injection; 2) Strict-Transport-Security (HSTS) with max-age=31536000 to enforce HTTPS; 3) X-Content-Type-Options: nosniff to prevent MIME-type confusion attacks; 4) X-Frame-Options: DENY or SAMEORIGIN to prevent clickjacking; 5) Referrer-Policy: strict-origin-when-cross-origin to protect user privacy; and 6) Permissions-Policy to control browser API access (camera, microphone, geolocation).

What causes an HTTP 429 Too Many Requests response and how should clients handle it?

An HTTP 429 status code indicates that the client has exceeded rate limits configured by the server or API gateway. Web APIs typically send a 'Retry-After' header indicating the number of seconds (or a specific timestamp) the client must wait before retrying. Clients should implement exponential backoff with jitter rather than bombarding the server with immediate retries.