Free HTTP Headers Checker

What Are HTTP Headers?

HTTP headers are pieces of information sent between a web browser and a web server during every HTTP request and response. They pass instructions, metadata, and directives that control how websites load, cache, secure, and deliver content. Every time you visit a URL, dozens of HTTP headers are exchanged behind the scenes — most users never see them, but they profoundly affect website performance, security, and functionality.

Our free HTTP headers checker intercepts and analyzes all response headers from any website, categorizing them into security headers, cache headers, CORS headers, content headers, and performance headers. The tool then provides specific recommendations for each missing or misconfigured header, helping Indian website owners and developers optimize their site's security and speed.

HTTP headers follow a simple name:value format. For example, Strict-Transport-Security: max-age=31536000 tells browsers to only load the site over HTTPS for the next year. Our header analyzer makes these technical details understandable and actionable for everyone from WordPress bloggers in Chennai to e-commerce developers in Hyderabad.

Why Should You Check HTTP Headers?

Whether you are a website developer in Bangalore, a business owner in Pune, or an IT admin managing servers in Mumbai, checking HTTP headers should be part of your regular website maintenance. Here is why:

Protect Against Hackers

Security headers like CSP, HSTS, and X-Frame-Options prevent XSS attacks, man-in-the-middle attacks, and clickjacking. Without them, your site is more vulnerable to common web exploits.

Improve SEO Rankings

Google considers page speed (affected by cache headers) and security (affected by security headers) as ranking factors. Properly configured headers can indirectly boost your search rankings.

Speed Up Your Website

Cache headers tell browsers how long to store files locally. Good cache config means returning visitors load your site instantly — a crucial factor for Indian users on mobile networks.

Fix CORS Issues

If your API or web fonts are blocked in browsers, it is likely a CORS misconfiguration. Our header checker identifies the exact CORS headers needed and their current values.

Ensure PCI Compliance

If you accept online payments, PCI-DSS requirements include having proper security headers. Our free header scanner helps verify your compliance.

Debug Issues Faster

When something breaks — a font not loading, an API call failing, a page not caching — HTTP headers are often the culprit. Our tool gives you the full header picture instantly.

Security Headers Explained

Security headers are HTTP response headers that instruct browsers to enable additional security features, protecting your website and its visitors from common attacks. Our free security headers checker scans for all of these:

Strict-Transport-Security (HSTS)

Forces browsers to only connect via HTTPS, preventing protocol downgrade attacks and SSL stripping. Set with: Strict-Transport-Security: max-age=31536000; includeSubDomains; preload. A max-age of at least 31536000 (1 year) is recommended.

Content-Security-Policy (CSP)

Controls which resources the browser is allowed to load, preventing Cross-Site Scripting (XSS) and code injection attacks. A strict CSP lists allowed sources for scripts, styles, images, frames, and other content types.

X-Content-Type-Options

Prevents browsers from guessing the content type (MIME sniffing). Set to 'nosniff' to ensure browsers respect your declared content types. This prevents attackers from disguising malicious files as safe content types.

X-Frame-Options

Prevents your website from being embedded in iframes on other domains, protecting against clickjacking attacks. Use 'SAMEORIGIN' to allow framing on your own domain only, or 'DENY' to block all framing entirely.

Referrer-Policy

Controls how much referrer information is sent when users click links from your site. The value 'strict-origin-when-cross-origin' or 'no-referrer' is recommended for privacy and security.

Permissions-Policy

Controls which browser features and APIs can be used on your page (camera, microphone, geolocation, etc.). Disabling unused features reduces your attack surface.

X-XSS-Protection

Enables the browser's built-in XSS filtering. While modern browsers have this built-in, setting X-XSS-Protection: 1; block provides an extra layer for older browsers. Note: CSP is more effective and modern替代.

Cache Headers Explained

Cache headers control how browsers and CDNs store your website's content locally. Properly configured cache headers dramatically reduce load times for returning visitors and reduce bandwidth costs — especially important for Indian websites where many users access the internet on mobile devices with limited data.

Key Cache Headers

Cache-Control

The most important cache header. Directives like 'max-age=3600' (cache for 1 hour), 'public', 'private', 'no-cache', and 'no-store' control exactly how content is cached.

Expires

Sets an exact date/time when the cached content expires. Largely replaced by Cache-Control but still useful for older browser compatibility.

ETag

A unique identifier for a specific version of a file. Browsers cache the ETag and send it back with requests to check if the file has changed — if not, a 304 Not Modified is returned, saving bandwidth.

Last-Modified

The date and time the resource was last modified. Browsers can use this with the 'If-Modified-Since' header to ask the server if content has changed since the last visit.

Age

Indicates how long the object has been in a CDN cache. A high Age value for dynamic content might indicate caching misconfiguration.

Pro tip: For Indian websites using Cloudflare (popular in India due to free tier and DDoS protection), cache headers interact with Cloudflare's CDN caching. Set Cache-Control: public, max-age=86400 for static assets to enable Cloudflare edge caching.

CORS Headers Explained

CORS (Cross-Origin Resource Sharing) headers control which websites are allowed to access your resources. If you run a web API, use Google Fonts, load images from CDN, or have a frontend on a different domain than your backend, CORS headers are critical.

Key CORS Headers

Access-Control-Allow-Origin

Specifies which origins (domains) can access your resources. Use '*' for public resources, or a specific domain like 'https://example.com' for restricted access.

Access-Control-Allow-Methods

Lists the HTTP methods (GET, POST, PUT, DELETE, etc.) allowed when accessing the resource. Should only include the methods your API actually supports.

Access-Control-Allow-Headers

Lists which HTTP headers can be used in the actual request (beyond the standard headers like Content-Type, Authorization, etc.).

Access-Control-Allow-Credentials

When set to 'true', allows cookies and authentication headers to be sent with cross-origin requests. Cannot be used with Access-Control-Allow-Origin: '*'.

Access-Control-Max-Age

How long (in seconds) the browser can cache the CORS preflight response. Higher values reduce the number of preflight requests for frequently called APIs.

Performance Headers Explained

Performance headers help optimize how content is delivered and loaded, directly impacting page speed — a critical metric for user experience and SEO, especially in India where internet speeds vary significantly across cities and towns.

Content-Encoding

Usually 'gzip', 'br' (Brotli), or 'deflate' — indicates the compression applied to the response body. Brotli (br) offers the best compression ratio, reducing file sizes by up to 90% compared to uncompressed content.

Transfer-Encoding

Indicates how the message body is encoded. 'chunked' is commonly used for streaming responses. For most static sites, Content-Encoding is more important.

Vary

Tells caches that the response varies based on certain request headers (e.g., Vary: Accept-Encoding means the cached version depends on whether the client supports gzip). Critical for correct CDN caching.

Connection

Controls whether the network connection stays open after the current transaction. 'keep-alive' reuses connections for multiple requests; 'close' closes it after each response. Keep-alive is standard for performance.

Timing-Allow-Origin

Specifies which origins are allowed to see timing information in the Resource Timing API. Useful for performance monitoring when using CDNs.

How to Fix Missing or Misconfigured Headers

Our free header checker identifies issues. Here is how to fix the most common ones:

Adding Security Headers (Nginx)

Add the following to your Nginx configuration in /etc/nginx/sites-available/default or your site config inside the server block:

add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;
add_header Content-Security-Policy "default-src 'self'; script-src 'self' 'unsafe-inline' https://www.google-analytics.com; style-src 'self' 'unsafe-inline' https://fonts.googleapis.com; font-src 'self' https://fonts.gstatic.com; img-src 'self' data: https:; connect-src 'self' https://api.example.com;" always;
add_header X-Content-Type-Options "nosniff" always;
add_header X-Frame-Options "SAMEORIGIN" always;
add_header Referrer-Policy "strict-origin-when-cross-origin" always;

Adding Security Headers (Apache)

Add to your .htaccess file in your website's root directory:

Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains; preload"
Header always set X-Content-Type-Options "nosniff"
Header always set X-Frame-Options "SAMEORIGIN"
Header always set Referrer-Policy "strict-origin-when-cross-origin"
Header always set Content-Security-Policy "default-src 'self'"

Adding Security Headers (Cloudflare)

If you use Cloudflare (popular among Indian websites), go to Speed → Optimization → HTTP/2 to Push or create a Page Rule for headers. You can also use Cloudflare Workers for custom header injection. Cloudflare automatically adds some security headers — verify with our free header analyzer.

HTTP Headers Best Practices

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Enable HSTS with a max-age of at least 31536000 (1 year) and include the 'preload' directive for maximum protection against SSL stripping attacks

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Implement a strict Content-Security-Policy (CSP) starting in report-only mode to identify violations before enforcement

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Set X-Content-Type-Options: nosniff on all responses to prevent MIME-type confusion attacks

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Use X-Frame-Options: SAMEORIGIN (or DENY) to prevent clickjacking on all pages, especially login and payment pages

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Configure Cache-Control properly: public for static assets (CSS, JS, images) with long max-age, private for user-specific content, no-store for sensitive data

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Enable Brotli compression (preferred over gzip) on your server or CDN for 15-25% better compression ratios

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If you use Cloudflare, leverage their automatic HTTP/2 server push and Polish image optimization features

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Set appropriate Vary: Accept-Encoding headers to ensure correct CDN caching of compressed and uncompressed content

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For APIs, set appropriate CORS headers instead of Access-Control-Allow-Origin: * (unless the API is truly public)

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Run our free HTTP headers checker regularly — at least monthly and after any server or CDN configuration changes

Frequently Asked Questions

Is the HTTP headers checker really free?

Yes, our HTTP headers analyzer is 100% free with no registration required. Enter any URL and get a complete breakdown of all response headers within seconds.

What headers does the tool check?

Our checker analyzes 40+ headers across 6 categories: security headers (HSTS, CSP, X-Frame-Options, etc.), cache headers (Cache-Control, ETag, Expires), CORS headers, content headers, performance headers, and general headers. It provides specific recommendations for each.

What is a good security header grade?

A grade of A or A+ means all critical security headers are properly configured. B is good but missing some headers. C through F indicate progressively more security vulnerabilities. Our free tool shows you exactly which headers are missing.

Do Indian hosting providers configure headers automatically?

Some do — Cloudways provides good default security headers on their managed cloud hosting. Hostinger India includes basic security headers on their premium plans. Shared hosting plans often have minimal or no security headers configured by default.

Will adding security headers break my website?

Some headers like CSP (Content-Security-Policy) can cause issues if not configured carefully — you might block legitimate scripts or styles. Always test CSP changes in a staging environment first. Simpler headers like HSTS and X-Content-Type-Options are safe to add without breaking sites.

How do I check headers on my WordPress site?

WordPress itself doesn't set most security headers — these come from your web server (Nginx/Apache) or CDN (Cloudflare). Our free header checker works on any website, including WordPress, Shopify, Wix, and custom-built sites.

What is the difference between request and response headers?

Request headers are sent BY the browser TO the server (e.g., User-Agent, Accept-Language, Authorization). Response headers are sent FROM the server TO the browser (e.g., Content-Type, Cache-Control, Set-Cookie). Our tool analyzes response headers only.

What are the most important security headers?

The five most critical security headers are: (1) Strict-Transport-Security (HSTS) — enforces HTTPS, (2) Content-Security-Policy — prevents XSS, (3) X-Content-Type-Options — prevents MIME sniffing, (4) X-Frame-Options — prevents clickjacking, and (5) Referrer-Policy — controls referrer information leakage.

How Our Free HTTP Headers Checker Works

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Header Categories We Check

Security Headers

Cache Headers

CORS Headers

Content Headers

Performance Headers

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Key Takeaways