JAEN

HTTP Header Builder

Build HTTP request headers from common presets and export as fetch, curl, or raw HTTP.

Input data is processed in your browser
Data is never sent to a server

Tool

Build HTTP headers from common presets or add custom ones. Export as fetch, curl, or raw HTTP.
2 headers
:
:
fetch("https://api.example.com/endpoint", {
  headers: {
    "Content-Type": "application/json",
    "Accept": "application/json"
  }
});

What is HTTP Header Builder?

This tool lets you add commonly used HTTP headers with a single click and easily assemble a combination of request headers.

The headers you build can be exported in three formats: a fetch() call, a curl command, or raw HTTP header syntax. It’s handy for preparing requests during API development or writing documentation.

How to Use

  1. Click a chip under "Common headers" (Content-Type, Authorization, etc.) to add it. Click again to remove it.
  2. Use "Add header" to freely add custom headers.
  3. Edit the header name and value for each row in the input fields. Values may be left empty.
  4. Switch between output tabs (fetch / curl / HTTP) to view the code in the format you need.
  5. Click "Copy" to copy the generated code to your clipboard.

FAQ

Which preset headers are supported?

Commonly used development headers are provided as presets, including Content-Type, Authorization, Accept, Accept-Language, User-Agent, Cache-Control, X-Requested-With, Origin, Referer, Cookie, X-API-Key, and If-None-Match.

Is the header name validated?

Yes. A warning is shown if a header name contains characters that aren't valid in an HTTP header name, or if a name is duplicated.

Can I use the generated code as-is?

The fetch and curl output use a sample URL (api.example.com). Replace it with your actual endpoint URL before use.

Is my data sent to a server?

No. All processing happens entirely in your browser.

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