cURL to Code Converter: A Complete Guide

By Bill Crawford · Published March 3, 2026 · 10 min read  ·  Last updated March 03, 2026

What Is a cURL to Code Converter?

A cURL to code converter takes a cURL command — the kind you copy from browser dev tools, API documentation, or a colleague's Slack message — and transforms it into working code in a programming language of your choice. Instead of manually translating flags like -H, -d, and -X into the equivalent fetch() options or requests.post() parameters, the converter handles the mapping automatically.

The cURL to Code Converter on this site supports JavaScript (fetch, axios, undici), Python requests, C# HttpClient, Go net/http, Java HttpClient, PHP cURL, Ruby net/http, and Kotlin OkHttp — all running entirely in your browser.

Why Convert cURL to Code?

cURL is the lingua franca of HTTP. Nearly every API's documentation provides cURL examples. Browser developer tools let you copy any network request as a cURL command. But cURL commands are not code you can drop into a JavaScript app, a Python script, or a Go service. The translation is mechanical but error-prone when done by hand — especially with complex headers, JSON bodies, or authentication schemes.

Common scenarios where a converter saves time:

• Integrating a third-party API where the documentation only shows cURL examples
• Reproducing a browser request in your backend code for debugging
• Migrating HTTP calls between languages during a project rewrite
• Generating boilerplate code from Postman or Insomnia exports
• Onboarding new developers who need working examples quickly

Anatomy of a cURL Command

Understanding what a cURL command contains helps you use the converter effectively. A typical command includes these parts:

curl -X POST "https://api.example.com/v1/users" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer abc123" \
  --data-raw '{"name":"Bill","role":"admin"}'

The Canonical Request Model

The converter's architecture uses a two-step process: first, it parses the cURL command into a language-agnostic canonical Request Model (a structured JSON object), then it renders that model into the target language. This means every output language gets the exact same interpretation of your command — there is no per-language parsing divergence.

The Request Model includes the HTTP method, full URL, separated query parameters, headers, structured body (with JSON detection), authentication details, and options like redirect following and insecure TLS. It also includes a warnings array that surfaces any ambiguity the parser encountered.

Supported Languages

JavaScript fetch

The Fetch API is the modern standard for HTTP requests in browsers and Node.js (18+). The converter generates fetch(url, options) with method, headers, and body. When the body is JSON, it wraps the object in JSON.stringify() automatically.

JavaScript axios

Axios is the most popular third-party HTTP client for JavaScript, used in both browser and Node.js environments. The output uses axios({ method, url, headers, data }) with the data field as a native object when JSON is detected.

Node.js undici

Undici is the high-performance HTTP/1.1 client that powers Node.js's built-in fetch. The converter generates import { request } from "undici" with destructured response handling.

Python requests

Python's requests library is the de facto standard for HTTP in Python. The converter uses requests.request(method, url, ...) with json= for JSON payloads and data= for form/raw bodies. Basic auth maps to the auth= parameter.

C# HttpClient

For .NET developers, the converter generates modern HttpClient code with HttpRequestMessage, StringContent, and SendAsync. Headers are added via TryAddWithoutValidation to handle both standard and custom headers.

Go net/http

The Go output uses the standard library's http.NewRequest with strings.NewReader for bodies and req.Header.Set for headers. It includes proper error handling with Go's idiomatic if err != nil pattern.

Java HttpClient

Java 11's built-in HttpClient is the modern replacement for Apache HttpClient. The converter generates HttpRequest.newBuilder() chains with BodyPublishers.ofString() for request bodies.

PHP cURL

PHP's native cURL extension maps almost directly from the command-line cURL flags. The converter generates curl_init(), curl_setopt(), and curl_exec() with proper option constants.

Ruby net/http

Ruby's standard library HTTP client is generated with Net::HTTP::Post.new(uri) and Net::HTTP.start with SSL support.

Kotlin OkHttp

OkHttp is the dominant HTTP client on the JVM and Android. The converter generates Request.Builder() chains with toRequestBody() for bodies and addHeader() for headers.

Working with Headers and Authentication

Headers are the most common source of conversion errors when done manually. A single cURL command might include content-type, authorization, accept, custom headers, and cookies — each needing different treatment in different languages.

The converter handles two authentication patterns automatically:

• Basic auth (-u user:pass): Detected and mapped to each language's native basic auth mechanism — auth= in Python, SetBasicAuth in Go, CURLOPT_USERPWD in PHP
• Bearer tokens (-H "Authorization: Bearer ..."): Passed as a header in all languages, with the token masked by default in output

Request Bodies: JSON, Form Data, and Raw

The parser distinguishes three body types:

• JSON: Detected when Content-Type is application/json or the body starts with { or [. The body is parsed into a native object and rendered using each language's JSON serialization.
• Form data: Detected when multiple -d key=value flags are present or Content-Type is application/x-www-form-urlencoded. Multiple -d flags are concatenated with &.
• Raw: Everything else is treated as a raw string body.

Secret Masking and Security

The converter includes built-in secret masking (enabled by default) that redacts likely sensitive values in the output: Authorization header values, bearer tokens, API keys in query strings, and long random strings that appear to be credentials or tokens.

Edge Cases and Gotchas

A few situations to be aware of:

• Multi-line commands: The parser handles backslash-newline continuations, so you can paste commands directly from documentation that spans multiple lines.
• Mixed quoting: Both single and double quotes are supported. Nested quotes require the outer and inner to be different types.
• Multiple -d flags: When all values are key=value pairs, they are combined into form-urlencoded. Otherwise they are concatenated with & and a warning is shown.
• Missing method: If no -X flag is present and a body is provided, the method defaults to POST (matching cURL's behavior).
• URL at end: The URL can appear before or after the flags.

Tips for Effective Use

• Use the Request Model tab to verify the parser understood your command correctly before copying generated code
• Enable Error Handling toggle when generating production code
• Turn off Mask Secrets when you need to copy working code with real credentials
• Use the Postman Collection tab to quickly import a request into Postman
• The Copy Normalized cURL button gives you a clean, consistently formatted version of your command