Inspect HTTP response headers
The MailDrop HTTP headers tool fetches any URL and displays the response headers the server sends back, laid out in a clean two-column table. Enter an address, click Check Headers, and you can immediately see values like the server software, content type, caching directives, cookies being set, redirect locations, and security policies. If you omit the scheme, the tool assumes https for you.
Response headers reveal a lot about how a site is configured and how seriously it takes security. Headers such as Strict-Transport-Security, Content-Security-Policy, X-Frame-Options, and X-Content-Type-Options protect visitors from downgrade attacks, script injection, and clickjacking, and their absence is worth knowing about. Developers also use header inspection daily to debug caching behavior, verify CORS settings, confirm compression, and trace redirect chains without opening browser developer tools.
The tool is free to use with no registration required. Combined with MailDrop temporary email, it is part of a practical privacy workflow: inspect how a site behaves and what it sets in your browser before deciding whether it earns your real email address or a disposable one.
Type or paste the address you want to check. Including https is optional; the tool adds it automatically if the scheme is missing, so example.com works just as well as the full URL.
Click Check Headers or press Enter. Our server requests the URL and captures the response headers, which avoids the cross-origin restrictions that prevent your browser from doing this directly.
Each header appears as a name and value pair. Scan for security headers, cookie attributes like Secure and HttpOnly, cache-control settings, and the Location header if the response is a redirect.
If you manage the site, adjust your server configuration and re-run the check to confirm changes took effect. Comparing headers before and after a deploy is a quick way to catch configuration regressions.
Headers are metadata a web server attaches to every response before the actual page content. They tell your browser what kind of content is coming, how long to cache it, which cookies to store, where to redirect, and what security rules to enforce. They are invisible to normal browsing but shape how every page behaves.
Look for Strict-Transport-Security to enforce HTTPS, Content-Security-Policy to limit where scripts load from, X-Content-Type-Options set to nosniff, X-Frame-Options or frame-ancestors to prevent clickjacking, and Referrer-Policy to limit data leakage. Missing headers do not prove a site is unsafe, but their presence signals attention to security.
Developer tools only show requests your browser makes, with your cookies and session attached. This tool fetches the URL from a neutral vantage point, which is handy for seeing what a first-time visitor receives, checking a site without visiting it in your own browser, or sharing results with someone who is not technical.
Requests pass through our server because browsers cannot read cross-origin headers directly, but lookups are anonymous: there is no account, no registration, and no profile connecting queries to you. The tool exists as a free utility, not a data-collection funnel.
Headers show you what a site sets in your browser, including tracking cookies, before you commit to it. If a signup page is heavy on trackers or light on security headers, that is a good moment to reach for a MailDrop disposable email address rather than your personal one, keeping the relationship easy to walk away from.