Request Header Builder
Build a custom HTTP request with specific headers, method, and body. Select the method, enter a URL, configure headers and body with a rich set of options, and see the raw request format generated in real-time. Perfect for API development, HTTP debugging, and learning the HTTP protocol - completely free, no signup required.
Build a custom HTTP request with specific headers, method, and body. See the raw request format generated in real-time.
Common headers (23)
GET /v1/users HTTP/1.1 Host: api.example.com Accept: application/json User-Agent: RequestHeaderBuilder/1.0
Features
Raw HTTP Request Generator
Build a complete raw HTTP request from a simple form. Select the method, enter a URL, add headers, and optionally include a body - the raw request output updates in real-time as you type.
Flexible Header Management
Add, remove, enable, or disable individual headers. Choose from a library of 23 common HTTP headers with preset values, or type custom header names and values. Each header can be toggled on/off without deleting it.
Pre-built Request Presets
Start from 4 pre-built request presets: REST API GET, POST JSON, DELETE Request, and Form Submission. Each preset sets the method, URL, headers, and body so you can see real-world examples instantly.
One-Click Copy & Analysis
Copy the generated raw HTTP request with a single click. The output shows the request line, headers, and body with colour-coded syntax. Character and byte counts are shown for your convenience.
Common Use Cases
API Development & Testing
Quickly build and inspect HTTP requests to REST APIs. Configure authentication headers, set content types, add query parameters, and see the exact raw request that will be sent to the server - perfect for API documentation and debugging.
HTTP Debugging & Troubleshooting
When an API call fails, use the builder to reconstruct the exact request that was sent. Verify headers, check the request format, and compare against the API specification to find mismatches in content types, authentication, or required headers.
Learning HTTP Protocol
Learn how HTTP requests are structured by building them interactively. See how the request line, headers, and body combine to form a complete HTTP message. Experiment with different methods, headers, and body formats to understand HTTP internals.
cURL / Postman Request Migration
When migrating requests from cURL to other tools or SDKs, use the builder to visualise the raw request structure. Paste the generated raw request into HTTP clients, or use it as documentation for your API integration team.
Security Header Verification
Build requests with specific security headers (Authorization, X-API-Key, X-CSRF-Token) and verify they are formatted correctly before using them in production. Check header casing, value encoding, and header ordering for security-sensitive endpoints.
Proxy & Middleware Configuration
Generate sample HTTP requests to test proxy servers, reverse proxies, API gateways, and middleware components. Verify that your infrastructure handles the request line, headers, and body correctly before deploying configuration changes.
About HTTP Request Structure
How HTTP Requests Are Structured
An HTTP request consists of three parts: the request line, headers, and an optional body. The request line contains the HTTP method (GET, POST, PUT, etc.), the path, and the HTTP version (e.g., HTTP/1.1). Headers are key-value pairs that provide metadata about the request, such as authentication tokens, content types, cache directives, and client information. The body, which is optional for methods like GET and DELETE, carries the payload data for POST, PUT, and PATCH requests.
HTTP Methods and Their Usage
GET requests retrieve resources and should not have a body. POST creates new resources and typically includes a JSON or form-encoded body. PUT replaces existing resources, PATCH applies partial updates, and DELETE removes resources. HEAD is like GET but returns only headers. OPTIONS discovers allowed methods, CONNECT establishes tunnels, and TRACE echoes back the request for debugging. Each method has specific semantics and best practices defined in the HTTP specification.
Common HTTP Headers Explained
Content-Type tells the server what format the request body is in (application/json, text/xml, etc.). Authorization carries credentials (Bearer tokens, Basic auth). Accept tells the server what response formats the client understands. User-Agent identifies the client software. Cache-Control directs caching behaviour. Host is required in HTTP/1.1 and identifies the target host. Cookies carry session state, and Origin/Referer provide context about where the request originated.
Why Raw Request Format Matters
Understanding the raw HTTP request format is essential for debugging network issues, writing correct API clients, configuring proxies and load balancers, and implementing web servers. Tools like cURL, Postman, and browser DevTools all work with raw HTTP requests under the hood. By seeing the exact format your request will take, you can catch formatting errors, missing headers, and encoding issues before they cause problems in production.
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