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cURL to Fetch & Axios Converter

Convert bounded curl commands into runnable fetch or axios code with explicit handling for every unsupported or non-representable option.

LocalNo command retention

Reviewed July 17, 2026

Guide, examples, and validation Show

About this tool

Turn a copied curl command into JavaScript request code without guessing what was silently dropped along the way.

  • Tokenizes single quotes, double quotes, ANSI-C quoting, escapes, line continuations, and comments, and stops with a clear error on pipes, redirections, command substitution, and unrecognized options.
  • Converts method, URL, headers, JSON, URL-encoded, raw, and multipart bodies, --data-urlencode, -G query promotion, basic auth, cookies, and --max-time timeouts into fetch and axios code.
  • Lists every dropped or browser-restricted option as an explicit note, flags unexpanded shell variables, and exports a versioned JSON report with the Authorization value redacted.

How to use cURL Converter

Paste a single curl command, convert it, review the parsed method, URL, headers, and notes, then copy the fetch or axios code or download the JSON report.

When this tool is useful

  • Porting a copied API example or DevTools 'Copy as cURL' command into application code.
  • Reviewing exactly which curl options survive a JavaScript translation before debugging a request.

Practical tips

  • Replace shell variables and @file references with literal values before converting.
  • Read every note: dropped options such as --insecure or --retry change behavior even though the code runs.

Examples you can test

Load an example, compare the result with the expected output, then replace it with your own input.

Convert a JSON POST

Example input

curl -X POST -H 'Content-Type: application/json' -d '{"a":1}' https://api.example.com

Expected output

fetch call with JSON.stringify body plus an axios equivalent

CORS and authentication on the target server still apply when the code runs in a browser.

Validation checklist

  • Confirm the parsed method, URL, and headers match the original command.
  • Resolve every warning note before running the code.
  • Remove embedded credentials before committing generated code.

Frequently asked questions

Which curl options are supported?

Common request options: -X, -H, -d and its --data variants, --data-urlencode, --json, -F, -G, -I, -u, -b with literal pairs, -A, -e, -L, -m, --url, and no-op flags such as -s and -v. Anything else stops the conversion with a named error instead of being ignored.

What happens to options fetch cannot express?

Options such as --insecure, --proxy, --retry, and --compressed are dropped and each one is reported as an explicit note, so the generated code never silently diverges from the original command.

Why does a command with @file or $(...) fail?

Reading local files and running shell substitutions cannot be reproduced by generated JavaScript. The converter asks you to paste literal content instead of emitting code that behaves differently.

Is the generated code safe to run in a browser?

The code is standard fetch or axios. Notes flag headers such as Cookie, User-Agent, and Referer that browsers restrict, and CORS on the target server still applies.

Are commands or credentials uploaded?

No. Parsing and code generation run locally. Credentials from --user appear in the generated code so it works, and the downloadable JSON report redacts the Authorization value.

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