Toolpaper

Convert cURL to Express

Paste any curl command and get Node.js code you can drop into a Express project. Node.js server routes calling third-party APIs with native fetch. Runs entirely client-side.

Quick answer

To convert a cURL command to Node.js, paste it into the Toolpaper workbench below. It parses the command in your browser and emits idiomatic Node.js code — headers, query string, request body, authentication (Bearer, Basic, API key), and cookies are all wired up automatically. No data is uploaded; conversion is fully client-side.

InputcURL command
MethodPOST·Headers1·Body40 B· Chars 132
OutputJavaScript · Node fetch(Node 18+)
// Node 18+ has global fetch
const response = await fetch("https://api.example.com/users", {
  method: "POST",
  headers: {
    "Content-Type": "application/json"
  },
  body: "{\"name\":\"Ada\",\"email\":\"ada@example.com\"}",
  redirect: "manual"
});
const data = await response.json();
Inspect

Example

A representative curl command for this scenario. Paste your own above to convert an exact match.

curl input
curl -X POST https://api.example.com/users \
  -H "Content-Type: application/json" \
  -d '{"name":"Ada","email":"ada@example.com"}'

Implementation notes

  • Generated code uses the native fetch primitive that fits Express's idioms — you can drop it into a controller, action, or service.
  • Errors and timeouts propagate naturally so you can wrap the call in Express's middleware and observability layer.
  • Environment variables replace inline secrets when you run the output through the Clean panel first.

Common mistakes

  • Blocking a request-scoped Express handler on a slow upstream — always set a timeout in the generated call.
  • Recreating an HTTP client per request instead of reusing a module-level one — kills keep-alive performance.
  • Leaking request-scoped headers (auth, tracing) to upstream calls — the generator only forwards what you paste.

Common questions

Which Node.js library does the Express output use?
native fetch, because it's the idiomatic choice inside Express. Switch libraries in the language dropdown any time.
Can I use this in a serverless function?
Yes. The generated code is a plain Node.js function; deploy it on Express's serverless target of choice.
Is any data sent to Toolpaper's servers?
No. Parsing and code generation run entirely in your browser.

Full Node.js reference on the cURL to Node.js hub, or open the main converter for all 18 targets.