HTTP Header Generator

Build HTTP headers for APIs and servers.

Build HTTP request headers for standard headers, curl, fetch API, and JSON in one place. All logic runs securely in your browser.

Smart Header Library

Authentication
Content & Negotiation
Caching
Security & Context

⚠ Invalid header name (only letters, numbers, and hyphens allowed)

0 Headers • 0 Characters

Generated Output

Add one or more headers on the left to generate standard, curl, fetch, and JSON output here.

Example HTTP Headers

These example headers show how real-world HTTP requests are typically configured when calling APIs or web services.

Authorization: Bearer YOUR_TOKEN Content-Type: application/json Accept: application/json User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64)
  • Authorization: Sends your access token or credentials so the API can authenticate the request.
  • Content-Type: Tells the server the format of the request body (for example JSON, form data, or XML).
  • Accept: Indicates which response format your client prefers to receive back.
  • User-Agent: Identifies the client (browser, script, or tool) that is making the request.

About HTTP Header Generator

The HTTP Header Generator is an essential tool for developers working with HTTP requests and API development. It allows you to create HTTP headers in the standard format, with a smart library of common headers for quick access. Perfect for API testing, curl and fetch command generation, and understanding HTTP header structure.

Use Cases:

  • Generating headers for API requests
  • Creating curl commands with headers
  • Testing HTTP endpoints with custom headers
  • Understanding HTTP header format
  • Configuring authentication headers
  • Setting content type and accept headers

Key Features:

  • Common headers library for quick access
  • Custom header creation
  • Multiple headers support
  • Standard HTTP header format, curl, fetch API, and JSON outputs
  • Copy headers to clipboard per output format
  • 100% browser-based - no server processing
By Muhammad Abdullah Rauf · Founder, EverydayTools.proUpdated 2026

Workflow guides

Step-by-step chains that connect related tools for common tasks.

Build a complete NGINX response header configuration

  1. Select the header types you need: security headers, caching directives, and content type.
  2. Copy the generated block into your NGINX location{} or server{} block, or into your Express/Koa middleware.
  3. Generate the CORS headers separately with CORS Header Generator if your API serves cross-origin browser requests.

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Frequently Asked Questions

What is the correct Content-Type for a JSON API response?

Use Content-Type: application/json; charset=utf-8. The charset parameter ensures clients interpret the body as UTF-8 encoded text. Many frameworks set this automatically, but when configuring NGINX, Apache, or a reverse proxy you need to set it explicitly in the response header block.

How do I set a Cache-Control header for static assets?

For immutable assets (versioned filenames): Cache-Control: public, max-age=31536000, immutable. For HTML files that change: Cache-Control: no-cache (forces revalidation but allows caching). For sensitive data: Cache-Control: no-store, private. This tool generates the correct directive combination for common use cases.

Which security headers should every web server include?

Key security headers: X-Content-Type-Options: nosniff (prevents MIME sniffing), X-Frame-Options: DENY (prevents clickjacking), Strict-Transport-Security: max-age=31536000; includeSubDomains (enforces HTTPS), and Content-Security-Policy (restricts resource origins). This tool generates all of them with correct syntax.

What is the difference between Authorization and WWW-Authenticate?

Authorization is a request header the client sends to authenticate (e.g. Authorization: Bearer <token>). WWW-Authenticate is a response header the server sends with a 401 to tell the client what authentication scheme is required (e.g. WWW-Authenticate: Bearer realm="api"). This tool generates both for documentation and server configuration.

Related Tools

More free tools for the same workflow.

cURL to Fetch Converter

Free cURL to fetch converter — paste any cURL command and instantly get the equivalent JavaScript fetch() code with all headers, methods, and body included. No signup needed.

API Mock Generator

Free API mock generator — create realistic mock API responses with custom status codes, response headers, and JSON body. Perfect for frontend development and testing. No signup.

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