What are HTTP headers?

HTTP headers are key-value pairs sent between a browser and web server with every request and response. They communicate metadata about the request, response, and content — including caching instructions, content type, and security policies.

Which security headers are most important?

The most important security headers are: Strict-Transport-Security (HSTS), Content-Security-Policy (CSP), X-Frame-Options (clickjacking protection), X-Content-Type-Options, and Referrer-Policy.

What is cache-control?

Cache-control is an HTTP header that tells browsers and CDNs how long to cache a resource. Setting appropriate cache-control values (e.g., 'max-age=31536000' for static assets) significantly improves repeat visit performance.

What is the X-Robots-Tag header?

X-Robots-Tag is an HTTP response header that provides the same indexation instructions as the meta robots tag, but applies to non-HTML resources like PDFs and images that can't have a meta tag.

Does HTTP header configuration affect SEO?

Yes. HSTS ensures HTTPS enforcement (positive SEO signal), cache headers improve page speed (Core Web Vitals), X-Robots-Tag controls indexation, and correct content-type headers ensure proper resource rendering.

Technical Seo

Free

HTTP Header Checker

View all HTTP response headers for any URL — identify security headers, caching, content-type, and more.

URL

What is HTTP Header Checker?

The HTTP Header Checker fetches the HTTP response headers of any URL and displays them in a readable, categorised format. It shows all response headers including status code, content-type, cache-control, security headers (HSTS, X-Frame-Options, CSP), and any SEO-relevant headers like X-Robots-Tag and Link canonical headers.

HTTP headers are invisible to website visitors but essential for SEO, security, and performance. Correct cache-control headers improve load speed. Security headers protect against XSS and clickjacking attacks. SEO headers like X-Robots-Tag can control indexation. Understanding and optimising your headers is an important part of technical SEO.

Why Use HTTP Header Checker?

Missing security headers leave your site vulnerable to attacks. Incorrect cache settings cause slow repeat visits. Missing compression headers increase load times. This tool gives you a complete snapshot of your server's HTTP response so you can identify and fix header configuration issues before they impact your site.

Key Features of HTTP Header Checker

✓Displays all HTTP response headers in organised categories
✓Checks for essential security headers (HSTS, CSP, X-Frame-Options, X-XSS-Protection)
✓Analyses cache-control and expires headers for caching configuration
✓Shows content-type and content-encoding headers
✓Identifies SEO headers: X-Robots-Tag, Link rel canonical

How to Use HTTP Header Checker

1
Enter the URL
Paste the URL you want to inspect into the HTTP header checker.
2
Fetch headers
Click 'Check Headers' to make a HEAD or GET request and capture the response headers.
3
Review all headers
Examine the full set of response headers organised by category.
4
Check for missing headers
Look for missing security headers (HSTS, CSP) and optimise cache-control settings.
5
Configure server headers
Update your web server (Nginx/Apache) or CDN configuration to add or fix headers.