Generator

HTTP Header Builder

Visually build HTTP request headers and export them as raw HTTP, cURL, JavaScript fetch, Python requests, or Node.js code. Everything runs in your browser.

Headers 2 active / 3 total

Validation

No issues detected.

Tips

  • Start typing in a header name field to see common header suggestions.
  • Click a suggested value pill to fill it in instantly.
  • Use the checkbox to disable a header without deleting it.
  • The body field appears for POST, PUT, PATCH, DELETE — JSON content-types auto-wrap with JSON.stringify.

Output

Switch tabs to copy the format you need.

About the HTTP Header Builder

The HTTP Header Builder lets you compose request headers visually — no syntax to memorize, no escaping mistakes. Add, reorder, enable, or disable headers, and export the request in five different formats: raw HTTP, cURL, browser fetch, Python requests, or Node.js fetch. The tool runs entirely in your browser, so credentials and tokens never leave your machine.

  • Autocomplete for 14+ standard HTTP headers
  • Quick-pick value chips for each common header
  • Toggle headers on or off without deleting them
  • Reorder headers with up/down buttons
  • Optional request body, with JSON auto-wrapping
  • Detects duplicate header names and missing values
  • Five output formats with copy-to-clipboard

How to Use the HTTP Header Builder

  1. 1

    Set the method and URL

    Pick the HTTP method (GET, POST, PUT, PATCH, DELETE, HEAD, or OPTIONS) and paste the target URL.

  2. 2

    Add your headers

    Type a header name — the autocomplete will suggest standard headers. Then enter the value, or click one of the suggested value chips that appear.

  3. 3

    Add a body if needed

    For POST, PUT, PATCH, or DELETE the body field appears. Paste JSON, form data, or any payload. JSON content types are auto-wrapped with JSON.stringify in fetch/Node output and json= in Python.

  4. 4

    Pick an output format

    Switch between Raw HTTP, cURL, fetch, Python, or Node.js using the tabs above the output. The output regenerates instantly as you edit.

  5. 5

    Copy and use

    Click Copy output to copy the generated request to your clipboard, then paste it into your terminal, IDE, or HTTP client.

Tip: Don't paste real production tokens into shared snippets. Use a placeholder like YOUR_TOKEN when sharing the generated cURL or fetch code with teammates.

Common Use Cases

REST API Testing

  • • Add an Authorization Bearer token quickly
  • • Set Content-Type and Accept for JSON APIs
  • • Generate cURL for terminal testing

Frontend Development

  • • Generate fetch() snippets for browser code
  • • Inspect request shapes before writing them
  • • Reproduce a header set across environments

Backend Integration

  • • Convert a working cURL into Node.js fetch
  • • Translate browser headers into Python requests
  • • Standardize headers across microservices

Debugging & Reproduction

  • • Recreate a problematic request from a bug report
  • • Toggle individual headers to bisect failures
  • • Share reproducible cURL examples in tickets

Webhook & Integration Setup

  • • Build signed webhook calls with custom headers
  • • Test webhook receivers from the command line
  • • Validate header casing and ordering

Learning HTTP

  • • See raw HTTP request lines as you build them
  • • Understand how headers map across libraries
  • • Compare GET, POST, PUT, and DELETE shapes

Frequently Asked Questions

Is my data safe? Does this tool send my headers anywhere?

No. Everything runs entirely in your browser using client-side JavaScript. Tokens, API keys, cookies, and any other header values you enter are never uploaded, logged, or transmitted to a server.

Which output formats are supported?

Five formats: Raw HTTP (the on-the-wire request), cURL (terminal command), fetch (browser JavaScript), Python requests, and Node.js fetch. Switch between them with the tabs above the output panel.

Can I add custom non-standard headers?

Yes. The autocomplete suggests common headers, but you can type any name — including custom X- headers, vendor-specific headers, or experimental ones. Names are case-insensitive in HTTP/2 but the tool preserves the case you type.

How do I disable a header without deleting it?

Uncheck the checkbox at the start of the row. Disabled headers stay in the list but are excluded from the generated output, which is useful when bisecting a failing request.

Why does the body field disappear sometimes?

The body field only shows for methods that allow a request body (POST, PUT, PATCH, DELETE, OPTIONS). GET and HEAD requests don't carry a body, so the field is hidden to keep the UI focused.

How does JSON body wrapping work?

If your Content-Type contains json, the tool wraps the body with JSON.stringify(...) in JavaScript output and uses the json= argument in Python. Otherwise the body is passed as a literal string. Set the Content-Type first to get the right wrapping.

What happens if I have duplicate header names?

The tool warns you in the Validation panel. Most HTTP servers will only honor the last value for a duplicate header (except for headers like Set-Cookie that allow multiple values), so the warning helps you catch unintended overrides.

Can I import an existing cURL command?

Not yet — this is a header builder, not a parser. You enter values manually and export them. For now, copy each -H flag's content into a header row.