HTTP Headers Tool

What are HTTP Headers?

HTTP headers are a core part of the Hypertext Transfer Protocol (HTTP), which is the foundation of data communication for the World Wide Web. They are a set of key-value pairs that are sent with both the client's request and the server's response. These headers carry essential metadata that tells the browser how to handle the content it receives. For example, a Content-Type header tells the browser whether the data is HTML, an image, or a JSON file, while a Cache-Control header specifies how long the browser should store the content before requesting a new version.

Key HTTP Headers to Look For

Our free header checker tool can help you analyze a variety of critical headers:

• Status Code: The first part of any HTTP response. A 200 OK means the request was successful, a 404 Not Found means the page doesn't exist, and a 301 Moved Permanently indicates a permanent redirect.
• Content-Type: Defines the media type of the resource, like text/html, image/jpeg, or application/json.
• Cache-Control: Specifies caching policies for both requests and responses, influencing how browsers and CDNs store content. Proper caching is crucial for website speed.
• Server: Identifies the web server software (e.g., Apache, Nginx) used to handle the request.
• X-Frame-Options: A security header that prevents clickjacking attacks by controlling whether a page can be loaded in an <iframe>.
• Strict-Transport-Security (HSTS): A security header that forces browsers to only connect to your site using HTTPS, preventing man-in-the-middle attacks.
• X-Content-Type-Options: A security header that prevents the browser from "sniffing" a response away from the declared content-type, which can be a security vulnerability.

Whether you're a developer troubleshooting an API, an SEO expert auditing a site, or a system administrator checking for security vulnerabilities, our HTTP header tool provides a simple yet powerful solution to get the information you need instantly.