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Curl to JavaScript Fetch Converter

Runs in browser

Convert curl commands to JavaScript fetch API code instantly. Supports all common flags: headers, POST data, auth, form data, and more.

Last updated 08 Apr 2026

Paste any curl command and get clean JavaScript fetch() code — both promise and async/await styles. Handles -X, -H, -d, -u, -F, and other common curl flags. All conversion runs in your browser.
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How to use

  1. 1

    Paste your curl command

    Copy a curl command from your terminal, API documentation, browser DevTools, or anywhere else and paste it into the input area.

  2. 2

    Choose output style

    Select Promise-based (.then/.catch) or async/await style — both produce identical functionality, just different syntax.

  3. 3

    Click Convert

    Click the Convert button to generate the equivalent JavaScript fetch() code.

  4. 4

    Copy the result

    Copy the generated fetch code and paste it directly into your JavaScript or TypeScript project.

Frequently asked questions

What curl flags does this tool support?
The converter handles the most common flags: -X (method), -H (headers), -d/--data/--data-raw/--data-binary (request body), -u/--user (Basic auth), -F/--form (multipart form), -b/--cookie (cookies), -A/--user-agent (User-Agent header), -L (follow redirects, flagged as note), --compressed (flagged), and -k/--insecure (flagged with a warning).
What's the difference between Promise and async/await output?
Both styles use the same fetch API and produce identical behavior. Promise style chains .then() and .catch() calls — useful for environments without async/await support. Async/await style uses the await keyword for sequential, readable code — the modern standard for new JavaScript projects.
Does this handle multi-line curl commands?
Yes. Multi-line curl commands that use backslash line continuations (the trailing \ at end of each line) are fully supported and correctly parsed.
How does Basic auth (-u) get converted?
The -u username:password flag is converted to an Authorization: Basic header with the base64-encoded credentials computed directly. The resulting header value is a static string like "Basic dXNlcjpwYXNz" — no runtime btoa() call is emitted in the output.
What happens with -F (form data)?
Form data flags (-F key=value) are converted to FormData objects with .append() calls. Note that when using FormData, you should not set the Content-Type header manually — the browser sets it automatically with the correct boundary.
Is any data sent to a server?
No. All parsing and code generation runs entirely in your browser. Your curl commands never leave your device.
Can I convert the output back to curl?
Not directly in this tool. You'd need to manually reverse the process — but the fetch code is straightforward enough to read and reconstruct the equivalent curl command if needed.
Why does it warn about --insecure (-k)?
The -k flag disables SSL certificate verification in curl. The fetch API in browsers always enforces certificate verification and cannot disable it, so this flag cannot be translated. The warning reminds you to fix the underlying SSL issue rather than disabling checks in production.

Curl to JavaScript Fetch Converter instantly transforms any curl command into

clean, readable JavaScript fetch() code. Whether you've copied a curl snippet

from API documentation, a browser's DevTools network panel, or a colleague's

instructions — this tool gives you production-ready fetch code in seconds.

Paste your curl command and choose between two output styles: Promise-based

(.then/.catch) for compatibility, or modern async/await for cleaner code.

The converter handles the full range of common curl flags: -X for method,

-H for headers, -d for request bodies (JSON or form-encoded), -u for Basic

authentication, -F for multipart form data, -b for cookies, and more.

All conversion happens in your browser — no data is sent to any server.

The converter correctly handles shell quoting (single quotes, double quotes,

backslash escapes), multi-line curl commands with backslash continuations,

and properly translates curl authentication flags into the equivalent fetch

Authorization headers.

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