HTTP Status Checker
Test any URL for its HTTP status code, response time, headers, and redirects.
Sends a live HTTP request and reports the status code, response time, server header, and redirect destination if applicable.
What HTTP Status Codes Tell You About Server Health
Every time a browser, crawler, or API client requests a resource from a web server, the server responds with a three-digit HTTP status code. That code is the fastest, most reliable signal of whether the request succeeded, was redirected, hit a client error, or failed on the server side. Status codes are grouped into five classes: 1xx informational, 2xx success, 3xx redirection, 4xx client errors, and 5xx server errors. Knowing how to read them is a core troubleshooting skill for developers, sysadmins, and SEO professionals alike.
For site owners, status codes have a direct impact on search rankings and user experience. A page returning 404 disappears from search results, while a misconfigured 302 redirect can prevent link equity from passing to the correct URL. Server errors in the 5xx range tell crawlers that something is broken, and persistent 5xx responses can lead to deindexing. Monitoring your status codes after a deployment, a DNS change, or a CDN migration is the quickest way to catch regressions before they affect real users.
This free HTTP status checker sends a live request to any URL and returns the status code, status text, response time in milliseconds, Content-Type, Server header, and the redirect target for 3xx responses. Each result includes a plain-English explanation of what the code means, so you can move from symptom to fix without consulting a reference table. Use it to validate a redirect chain, confirm a page is reachable, or diagnose a 5xx error reported by a monitoring service.
How to Use the HTTP Status Checker
- Enter the full URL you want to test (for example,
https://example.com/page). If you omit the protocol,https://is added automatically. - Click the Check Status button. The tool sends an HTTP request to the server and captures the full response.
- Review the status code, response time, headers, and redirect target (if any). Color coding shows green (2xx), yellow (3xx), or red (4xx/5xx) so you can spot problems at a glance.
Common HTTP Status Codes Explained
The codes below cover the responses you will encounter most often when debugging websites and APIs. Understanding each one helps you pinpoint where a failure originates.
200 OK
The request succeeded. The server returned the requested resource as expected. This is the status code you want for every reachable page.
301 Moved Permanently
The resource has been permanently relocated to a new URL. Search engines transfer ranking signals to the new address, and browsers cache the redirect.
302 Found
A temporary redirect. The resource is at a different URL for now, but search engines keep the original URL indexed. Use during maintenance or A/B tests.
400 Bad Request
The server could not understand the request due to malformed syntax. Often caused by a typo in the URL, invalid query parameters, or a corrupt request body.
401 Unauthorized
Authentication is required and has either not been provided or has failed. The client must supply valid credentials before the resource can be accessed.
403 Forbidden
The server understood the request but refuses to authorize it. Common causes include incorrect file permissions, IP blocking, or missing index files.
404 Not Found
The requested resource does not exist on the server. Check for typos, verify the file or route exists, and review your web server configuration.
502 Bad Gateway
The gateway or proxy server received an invalid response from an upstream server. Typically means a backend process (PHP-FPM, Node.js) has crashed or is unreachable.
503 Service Unavailable
The server is temporarily unable to handle the request, usually due to maintenance or overload. The server is running but deliberately refusing connections.
504 Gateway Timeout
The gateway did not receive a timely response from the upstream server. Often caused by slow database queries, overloaded backends, or tight timeout settings.
Frequently Asked Questions
What is a 502 Bad Gateway error?
A 502 error means your server (e.g., Nginx) received an invalid response from the upstream server (e.g., PHP-FPM, Node.js). Common causes: upstream process crashed, wrong upstream port/socket, firewall blocking, or upstream timeout.
How do I fix a 404 Not Found error?
Check the URL for typos, verify the file exists on the server, check web server configuration (Nginx try_files, Apache .htaccess), and ensure the route is properly configured. For CMS sites, check permalink settings.
What is the difference between 301 and 302 redirects?
301 means permanent redirect (SEO equity passes to new URL, browsers cache it). 302 means temporary redirect (SEO equity stays with original URL, browsers re-check on each visit). Use 301 for domain moves, 302 for maintenance.
What does HTTP 503 Service Unavailable mean?
The server is temporarily unable to handle the request, usually due to maintenance or overload. Unlike 502, the server itself is running but refusing connections. Check server load, connection limits, and maintenance mode settings.
How do I check HTTP response headers?
Use this tool to check any URL's headers. Alternatively, use curl -I https://example.com in terminal, or open browser DevTools (F12) and navigate to the Network tab, then click any request to see its headers.