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Technical SEO · Free Tool

Free HTTP Headers Checker

HTTP headers control security, caching, and browser behavior. This tool shows every response header your server sends — and audits the critical security headers (HSTS, CSP, X-Frame-Options, X-Content-Type-Options, Referrer-Policy) so you can see exactly what's missing.

What This Tool Checks

  • check_circleAll HTTP response headers displayed in a readable format
  • check_circleSecurity headers audit: HSTS, Content-Security-Policy, X-Frame-Options, X-Content-Type-Options, Referrer-Policy
  • check_circleCache-Control header: max-age, no-store, no-cache analysis
  • check_circleContent-Encoding: gzip/brotli compression detection
  • check_circleContent-Type and charset verification
  • check_circlePass/fail security grade for each critical header
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Why This Matters for SEO

Security headers protect your site and users from common attacks like clickjacking (X-Frame-Options), MIME type sniffing (X-Content-Type-Options), and cross-site scripting (Content-Security-Policy). Google's Chrome browser and security scanning tools like Lighthouse audit these headers. Missing security headers can also affect your perceived trustworthiness in Google's quality signals.

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Frequently Asked Questions

What are HTTP headers?expand_more
HTTP headers are metadata sent alongside every web request and response. Response headers (from server to browser) control how the browser handles the page: caching behavior (Cache-Control), security policies (Content-Security-Policy), encoding (Content-Encoding), and HTTPS enforcement (Strict-Transport-Security). They're invisible to users but critical for security, performance, and SEO.
What security headers should my website have?expand_more
The essential security headers are: (1) Strict-Transport-Security (HSTS) — forces HTTPS. (2) X-Frame-Options — prevents your site from being embedded in iframes (clickjacking protection). (3) X-Content-Type-Options: nosniff — prevents MIME type sniffing attacks. (4) Referrer-Policy — controls what referrer information is sent with requests. (5) Content-Security-Policy — restricts which resources can load. Google's Lighthouse audit flags missing security headers.
Does Cache-Control affect website performance?expand_more
Yes, significantly. A well-configured Cache-Control header tells browsers how long to store resources locally, reducing repeat visits' load times drastically. For static assets (CSS, JS, images), setting a long max-age (e.g., 1 year) with content-based cache-busting is best practice. For HTML pages, using no-cache or short max-age ensures users always get fresh content. Correct caching headers directly improve your Core Web Vitals scores.
What is Content-Encoding and does it affect speed?expand_more
Content-Encoding indicates whether your server compresses responses before sending them. Gzip compression reduces text-based resources (HTML, CSS, JS) by 60–80%, dramatically reducing transfer sizes. Brotli is newer and offers even better compression. If your server isn't sending gzip or brotli-encoded responses, you're sending much more data than necessary, directly hurting load times and Core Web Vitals.
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Monitor headers across your entire site

PerfBee checks HTTP headers on every page during crawls — flagging missing security headers and misconfigured cache policies automatically. Get daily crawl reports, broken link alerts, Core Web Vitals tracking, and AI fix suggestions — across your entire site.

  • checkCrawl unlimited pages — daily, automatic
  • checkBroken link detection across your whole site
  • checkCore Web Vitals & Lighthouse audits per page
  • checkAI-powered code fix suggestions
  • checkWhite-label PDF reports for clients
  • checkEmail alerts for new issues & downtime
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