HTTP Request Builder

Use the http request builder tool online for practical file workflows. Add limitations, troubleshooting, related tools, and the safe processing note.

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HTTP Request Builder

Build and test HTTP API requests with custom headers, body, and parameters.

HTTP Request Builder Features

A lightweight browser-based HTTP client for API testing.

All HTTP Methods

Supports GET, POST, PUT, PATCH, DELETE, HEAD, and OPTIONS requests.

Headers and Body

Set custom request headers and send JSON or text request bodies.

Response Viewer

View response body, headers, status code, and response time.

How to Build and Send an HTTP Request

  1. Set the method and endpoint

    Pick a method from the dropdown (GET, POST, PUT, PATCH, DELETE, HEAD, or OPTIONS) and type the full endpoint URL into the address field, including the https prefix.

  2. Add headers, params, and a body

    Use the Headers tab to add key-value header rows such as Content-Type or Authorization. Use the Params tab to add query string pairs, which are URL-encoded and appended to the URL automatically. For POST, PUT, or PATCH, switch to the Body tab and paste your JSON or raw text payload.

  3. Send and read the response

    Click Send. The tool fetches the URL directly from your browser and shows the status code, status text, and round-trip time in milliseconds. Switch between the Body and Headers response tabs to inspect the result, where valid JSON is automatically pretty-printed with indentation.

Request Tabs and What Each One Controls

The builder splits a request into three editable areas plus the method and URL. Knowing what each tab affects helps you avoid common setup mistakes when testing an API.

Tab or fieldWhat it setsHow it is applied
Method dropdownThe HTTP verbSent as the request method; GET and HEAD skip any body you enter
URL fieldThe target endpointUsed as-is, with encoded query params appended when present
Headers tabCustom request headersEach non-empty key-value row is sent as a header, including auth headers
Params tabQuery string valuesURL-encoded and joined with and added after a question mark
Body tabRequest payloadSent verbatim as the body for non-GET, non-HEAD methods
Response tabsResult inspectionShow the returned body (JSON auto-formatted) and the response headers

When This Tool Fits Your Task

Quick REST checks

Reach for this when you want to confirm an endpoint returns the expected status and JSON without opening a desktop client or writing a script.

Inspecting headers

Use it when you need to read the exact response headers a server sends back, such as content type, caching, or rate-limit values.

Testing auth headers

It works well for trying Bearer tokens, API keys, or Basic auth, since you add the Authorization header by hand in the Headers tab.

When CORS blocks you

For APIs that do not allow browser origins, a server-side client or command-line tool is the better choice, since the browser will reject those cross-origin calls.

Common Problems and Fixes

Request failed with a CORS note

The browser blocks responses from servers that do not send permissive cross-origin headers. This is a browser security rule, not a tool fault. Test an API that allows browser origins, or use a server-side client for endpoints that do not.

My JSON body is ignored

Bodies are only sent for non-GET and non-HEAD methods. Switch the method to POST, PUT, or PATCH, and add a Content-Type header of application/json so the server parses it correctly.

A header or param did not apply

Rows with an empty key are skipped. Make sure the key field on each header or param row is filled in; blank-key rows are dropped before the request is sent.

Response shows raw text instead of formatted JSON

Automatic indentation only happens when the body parses as valid JSON. If the server returns malformed JSON, HTML, or plain text, the response is shown exactly as received.

References

  1. HTTP - MDN Web Docs, Mozilla
  2. HTTP request methods - MDN Web Docs, Mozilla
  3. Fetch API - MDN Web Docs, Mozilla
  4. HTTP headers - MDN Web Docs, Mozilla
  5. Cross-Origin Resource Sharing (CORS) - MDN Web Docs, Mozilla
  6. RFC 9110: HTTP Semantics - IETF
  7. HTTP response status codes - MDN Web Docs, Mozilla
  8. Clipboard.writeText() - MDN Web Docs, Mozilla