HTTP Header Viewer 🌐

Overview

HTTP Header Viewer helps developers and testers analyze the response headers returned by web servers. You can analyze headers for a single URL or multiple URLs in batch mode -- all processed securely via a Next.js API route.

Key Features

• 🔍 Single URL Analyzer -- fetch and display response headers for one URL.
• 📦 Batch Header Fetcher -- analyze multiple URLs at once, each with its own status and headers.
• 📑 Header Search & Copy -- quickly filter, copy, or export headers as JSON.
• 📈 Response Status View -- view each URL’s HTTP status code and header count instantly.
• 🧠 Educational Insights -- learn what each HTTP header means and why it’s important.

Common Response Headers Explained

• Content-Type: Defines the data format of the response, such as text/html or application/json.
• Cache-Control: Instructs browsers and proxies on how to cache the response (e.g., max-age=3600).
• Content-Encoding: Specifies compression (e.g., gzip, br) used to reduce response size.
• Server: Indicates which software (e.g., nginx, Apache) handled the request.
• Strict-Transport-Security: Enforces HTTPS, telling browsers to always connect securely (HSTS policy).
• Access-Control-Allow-Origin: Defines which external origins can access the resource -- used in CORS.
• ETag: A unique ID for a version of a resource; helps optimize caching and validation.
• Set-Cookie: Sends cookies to the browser, often used for authentication and sessions.
• X-Frame-Options: Prevents your site from being embedded in iframes to stop clickjacking.
• Content-Security-Policy (CSP): Defines what external resources (scripts, styles, images) a site can load.