---
title: "curl to JavaScript Converter - fetch Code Generator"
description: "Convert curl commands to JavaScript fetch code online. Headers, cookies, JSON bodies, and FormData translated in your browser. Free, no signup."
url: https://webscraping.ai/tools/curl-converter/javascript
markdown_index: https://webscraping.ai/llms.txt
---
FREE TOOL

# curl to JavaScript Converter

Paste a curl command, get working `fetch` code for the browser or Node.js 18+ — headers, JSON bodies, form data, and timeouts translated. Runs in your browser, no signup.

curl command

Conversion runs entirely in your browser — the command (and any tokens or cookies in it) is never sent to a server. Tip: DevTools Network tab → right-click a request → Copy as cURL.

```python

```

## Scraping a real site? Skip the blocks

Hand-copied curl headers go stale, and sites still block datacenter IPs. The same request through the WebScraping.AI API gets rotating proxies, headless Chrome rendering, and unblocking in one call — your custom headers and cookies are forwarded via the `headers` parameter. Shown with the [official client library](https://webscraping.ai/docs#sdks) of your choice:

```bash

```

[Get a Free API Key](https://webscraping.ai/auth/sign_up)[View API Documentation](https://webscraping.ai/docs)

2,000 free API credits · No credit card required

Convert curl to other languages: [curl to Python](https://webscraping.ai/tools/curl-converter/python)[curl to Node.js](https://webscraping.ai/tools/curl-converter/node)[curl to PHP](https://webscraping.ai/tools/curl-converter/php)[curl to Go](https://webscraping.ai/tools/curl-converter/go)[curl to Java](https://webscraping.ai/tools/curl-converter/java) · [all languages](https://webscraping.ai/tools/curl-converter)

## What the generated fetch code does

The output is modern `async/await` fetch: `-H` headers become the `headers` object, a JSON body becomes `JSON.stringify(…)`, form-encoded data becomes `URLSearchParams`, `-F` uploads become `FormData`, `-u` turns into a Basic `Authorization` header built with `btoa()`, and `-m` maps to `AbortSignal.timeout()`. The same code runs in browsers and in Node.js 18+, where fetch is built in.

Two fetch-specific caveats the converter flags: browsers own the `Cookie` header (a cookie-carrying request only works verbatim in Node.js), and fetch has no proxy option — for `-x` you need Node with undici's `ProxyAgent`, or [axios](https://webscraping.ai/tools/curl-converter/node).

## Frequently asked questions

How do I convert a curl command to JavaScript fetch?

Paste the command into the converter above — it outputs fetch code with async/await instantly, in your browser. Headers, JSON and form bodies, basic auth, file uploads, and timeouts are translated. Nothing you paste is sent to a server.

Why does the request work in curl but fail in the browser with a CORS error?

curl isn't subject to the browser's same-origin policy; fetch from a web page is. If the target API doesn't send CORS headers, the browser blocks the response. Run the same code in Node.js 18+ (no CORS there), or route the request through a server-side proxy or scraping API.

Should I use fetch or axios?

fetch needs no dependency and covers most cases — it's the default choice in both browsers and Node.js 18+. axios adds conveniences fetch lacks: automatic JSON parsing, proxy support, interceptors, and wider legacy-Node compatibility. This tool generates both — pick Node.js (axios) in the dropdown.

The fetch code gets a 403 that curl doesn't — why?

Node's fetch has its own TLS fingerprint and your server's IP has its own reputation; anti-bot systems check both, plus JavaScript challenges. Copying more headers rarely fixes it durably. The WebScraping.AI API runs the request through rotating proxies and real headless Chrome instead.

## Related

[Web scraping with JavaScript](https://webscraping.ai/blog/web-scraping-with-javascript): Fetching, parsing, and scraping dynamic pages in JS.

[JavaScript scraping libraries](https://webscraping.ai/blog/javascript-web-scraping-libraries): Cheerio, Puppeteer, Playwright, and friends compared.

[curl commands for scraping](https://webscraping.ai/blog/curl-commands-for-web-scraping): The curl options that matter for scraping, explained.

## fetch code ready? Make it unblockable.

Same request, plus rotating proxies, headless Chrome, and JS rendering — one API call from JavaScript.

[Start Free Trial](https://webscraping.ai/auth/sign_up)[View API Documentation](https://webscraping.ai/docs)