HTTP Headers Checker
Inspect response headers returned by any server. Check status codes, identify web server configurations, and evaluate security headers instantly.
What are HTTP Response Headers?
HTTP response headers are like the packing slips for digital content. When a web server answers your search request by sending a website file, it also sends a package of metadata tags. This packet contains specific instructions meant for the user's browser.
These parameters tell the browser what server software is operating, how many seconds to cache the assets locally, the file encoding type, and most importantly, what security limits and permissions to apply to scripts or frames on the site page.
Why should you check HTTP headers?
Prevent Clickjacking attacks
Audit parameters like X-Frame-Options to block hackers from placing your website in invisible background frames, protecting your users from accidental clicks that log personal details.
Enforce HTTPS traffic
Ensure your Strict-Transport-Security (HSTS) settings are active. HSTS stops attackers on public Wi-Fi networks from forcing users' devices onto insecure HTTP pages.
Audit backend server signatures
Inspect what technologies your systems reveal. Hiding specific server banners (like exact Nginx or Apache versions) prevents attackers from exploiting known system vulnerabilities.
Debug cache configurations
Check your Cache-Control headers to ensure browser clients know when to retrieve new page changes versus when to load files from local disk memory.
How to inspect headers
Paste the target URL
Copy the full URL (including subdomain) of the site you want to inspect into our tool above and click check.
Check security score
Review our security header audit table to confirm which critical defensive headers are missing on the target host.
Analyze raw headers
Click Show Raw Headers to inspect exact header fields like Cache-Control, Connection, Server, and Set-Cookie details.
Frequently Asked Questions
What are HTTP response headers?
HTTP response headers are metadata lines sent by a web server to a browser alongside the requested page. They provide details about the file size, server software, content encoding, cache guidelines, and instructions on how to handle security policies.
Why are HTTP security headers important?
Security headers act as a shield, instructing the browser to restrict dangerous actions. They help block common exploits like cross-site scripting (XSS), clickjacking, drive-by downloads, and MIME-type sniffing, adding a robust layer of protection over your core application code.
What is the Strict-Transport-Security (HSTS) header?
The Strict-Transport-Security header forces browsers to only connect to your site over a secure HTTPS link, even if a user explicitly types http://. This stops man-in-the-middle attacks where hackers try to intercept data by forcing a downgrade to HTTP.
What happens if Content-Security-Policy (CSP) is missing?
Without a Content-Security-Policy header, your website is more vulnerable to malicious script injections. A hacker could inject bad code that steals cookies, logs keystrokes, or loads dangerous external assets because the browser has no rules restricting where scripts can load from.
What is the X-Frame-Options header used for?
X-Frame-Options tells the browser whether your site is allowed to be rendered inside an iframe on another domain. Setting this to 'DENY' or 'SAMEORIGIN' protects your visitors from clickjacking, where hackers overlay invisible frames to steal clicks.
Can I see request headers using this tool?
No, this tool specifically checks response headers, which are sent by the server back to the client. Request headers are sent by your browser to the server (like User-Agent and Cookies). To inspect request headers, use your browser's developer inspect tool.
