Curl ↔ Fetch Converter

Convert curl commands to JavaScript fetch() and back — instantly

What is a Curl ↔ Fetch Converter?

A Curl ↔ Fetch Converter is an essential developer tool that instantly translates between two of the most popular HTTP request formats: cURL (a command-line client) and JavaScript's fetch() API (a native browser method).

Developers spend hours manually rewriting API requests between terminal commands and browser code. This converter eliminates that friction — paste a curl command from Chrome DevTools or Postman and get production-ready JavaScript fetch code in one click.

cURL → fetch()fetch() → cURLAPI TestingDevTools Export

Key Benefits

  • ✓
    Zero Manual RewritingInstantly convert API formats without syntax errors.
  • ✓
    DevTools CompatiblePaste exports directly from Chrome, Firefox & Postman.
  • ✓
    Supports All MethodsHandles GET, POST, PUT, DELETE, PATCH with headers.
  • ✓
    Privacy FirstYour API keys and tokens stay in your browser only.

cURL vs JavaScript fetch()

Understanding the two formats you will convert between

🖥️ cURL Command

cURL is a powerful command-line tool for making HTTP requests from your terminal. It is the universal format for API documentation examples and is natively supported on Linux, macOS, and Windows 10+.

  • → Used in terminal / shell scripts
  • → Exported by Chrome, Postman, Insomnia
  • → Great for server-side automation & CI/CD
  • → Cross-platform: works on all OS
  • → Supports proxy, cookies, certificates

🌐 JavaScript fetch()

The Fetch API is the modern, built-in browser method for making HTTP requests in JavaScript. It returns Promises, making it perfect for async/await patterns in React, Next.js, and vanilla JS applications.

  • → Native to all modern browsers
  • → Returns a Promise (supports async/await)
  • → Perfect for React, Next.js, Vue apps
  • → Integrated with the JavaScript ecosystem
  • → Cleaner code with response.json() chaining

How to Use This Converter

Convert between curl and fetch in four simple steps

01
🔁

Choose Direction

Select 'Curl → Fetch' to convert a curl command to JavaScript, or 'Fetch → Curl' to go the other way.

02
📋

Paste Your Code

Copy a curl command from Chrome DevTools (Network tab → right-click → Copy as cURL) or Postman, then paste it in.

03
⚡

Click Convert

Hit the Convert button. The tool instantly parses all headers, methods, and body data, producing clean output.

04
✅

Copy & Use

Copy the output code directly into your React component, Node.js script, or API documentation.

Real-World Use Cases

🔵

Chrome DevTools Exports

Right-click any network request in Chrome DevTools → 'Copy as cURL'. Paste it here to instantly get a fetch() snippet you can paste into your React or Next.js component.

From DevTools → To React
🟠

Postman to Frontend Code

Export any tested Postman request as cURL, then convert it to clean JavaScript fetch() code. Eliminates manual translation and prevents header/body formatting mistakes.

Postman → fetch()
📄

Writing API Documentation

Many API docs show only curl examples. Convert them to fetch() so your frontend team can copy-paste directly into JavaScript projects without manual adaptation.

API Docs → JS code
⚙️

Backend Testing Scripts

Convert your JavaScript fetch() call to a curl command to quickly test API endpoints from a CI/CD pipeline, Docker container, or a fresh server environment.

fetch() → Shell script

Common cURL Flags This Tool Supports

cURL FlagMeaningfetch() Equivalent
-X POSTSets the HTTP methodmethod: 'POST'
-H 'Content-Type: ...'Adds a request headerheaders: { 'Content-Type': ... }
-d '{ ... }'Sends a request bodybody: JSON.stringify({ ... })
--data-rawSends raw body databody: 'raw string'
-u user:passBasic authenticationAuthorization: Basic ...
-H 'Authorization: Bearer ...'Bearer token authheaders: { Authorization: 'Bearer ...' }

API Request Best Practices

Never Paste Real Secrets

Avoid pasting production API keys or tokens into any online tool. Use placeholder values for testing.

Validate Headers

Always double-check Content-Type and Authorization headers after conversion to ensure they are formatted correctly.

Use async/await

Wrap your converted fetch() code in an async function for cleaner error handling with try/catch blocks.

Handle Errors

Always check response.ok before calling response.json() to gracefully handle API errors in your app.

Explore Related Tools

🔗

URL Encoder / Decoder

Safely encode query parameters and special characters in your API URLs.

🔓

JWT Decoder

Decode and inspect Bearer tokens found in your curl/fetch Authorization headers.

📋

JSON Formatter

Validate and beautify the JSON body data in your API requests before sending.

🔤

Base64 Converter

Encode Basic Auth credentials (user:pass) to Base64 for your Authorization header.

Frequently Asked Questions

Everything you need to know about curl, fetch(), and API request conversion.

We do not store your input. For curl → fetch conversion, the command is sent once to our Next.js API route for parsing (same as your site host) and is not saved. Fetch → curl runs entirely in your browser. Avoid pasting production secrets on any online tool when possible. Always use placeholder tokens when testing API converters online.
cURL is a command-line HTTP client used in terminals, shell scripts, CI/CD pipelines, and exported by tools like Postman and Chrome DevTools. fetch() is the modern, built-in browser JavaScript API for making HTTP requests that returns Promises and works natively in all modern browsers. This tool bridges both formats instantly so you can switch between terminal testing and browser-based JavaScript development.
Yes, absolutely! Paste a curl command from Chrome DevTools or Postman that includes -H "Content-Type: application/json", -d or --data-raw with a JSON body, and -H "Authorization: Bearer your-token". The converter will accurately map all of these to the correct fetch() options object including method, headers, and body properties.
Yes. Switch to "Fetch → Curl" mode and paste any standard fetch(url, { method, headers, body }) pattern. The converter generates the equivalent curl command including -X method flags, -H header flags, and -d body data flags. Note: very complex JavaScript logic with variables or dynamic values may require minor manual adjustment after conversion.
Open Chrome DevTools (F12), go to the Network tab, trigger the API request on the webpage, then right-click on the request in the Network panel, hover over "Copy", and select "Copy as cURL (bash)" or "Copy as cURL (cmd)" depending on your OS. Paste the copied command directly into this converter to get clean JavaScript fetch() code.
When enabled, the converter wraps your converted fetch() call inside an async function and automatically adds await response.json() to parse the JSON response. This is extremely useful for React components or Node.js scripts where you need a complete, runnable async function rather than just a bare fetch() call that returns a Promise.
curl is natively available on Windows 10 (version 1803 and later) and Windows 11 via the built-in Command Prompt and PowerShell. On older Windows versions, you can install it via winget, Chocolatey, or by downloading directly from curl.se. Alternatively, Git for Windows also includes curl in its bundled Git Bash terminal.
This usually happens when the original curl command uses --data-urlencode or a non-JSON body format. Ensure your curl -d flag uses valid JSON wrapped in single quotes (on Mac/Linux) or double quotes (on Windows CMD). Also confirm that your curl command includes the -H "Content-Type: application/json" header so the converter can correctly identify and format the request body.

📚 Related Tutorials & Resources

Deepen your understanding of API testing, HTTP requests, and JavaScript development.

🌐

REST API Design Guide

Learn how to design clean, RESTful APIs and test them with curl and fetch.

Read More →
🐳

Docker & API Testing

How to use curl commands inside Docker containers to debug containerized APIs.

Read More →
⚡

Optimizing API Calls

Performance tips for making faster, more efficient fetch() requests in your web app.

Read More →
View All Tutorials→