How do I convert a curl command to JavaScript fetch?

Paste the curl command. Specway parses the URL, method, headers, and body, then generates equivalent code in your chosen language. Switch between JS fetch, Node fetch, Axios, Python requests, and Go net/http with one click. Copy the result and paste into your code.

Which curl options are supported?

The big ones: -X (method), -H (header), -d / --data / --data-raw / --data-binary (body), -u (basic auth), --request, --header. Less common flags (--insecure, --cert, --output, --form for multipart) are ignored — convert those manually because the equivalents differ across languages.

Why does my converted Python code fail?

Three usual causes: (1) the curl used POST without -d but the Python output assumes JSON body — set the right body type. (2) the URL has query params with characters Python's requests library encodes differently — pass params= dict instead. (3) authentication uses cookies that curl picked up from --cookie-jar — re-implement explicitly with requests.Session.

What's the difference between fetch, node-fetch, and axios?

fetch is the browser/Bun/Deno/Node 18+ standard. node-fetch is the legacy library for Node <18 (no longer needed in 2026 unless you support old runtimes). Axios is third-party, has nicer ergonomics for body/headers and built-in JSON handling. Pick fetch for modern Node, axios if your team prefers its DX.

Does the converter handle multipart form-data?

Not yet — multipart with curl's --form flag has language-specific equivalents (FormData in JS, requests.post(files=) in Python, multipart.NewWriter in Go) that vary in subtle ways. For now, use plain JSON or url-encoded bodies. We'll add multipart support if there's demand.

Why does the generated Go code do nothing with errors?

For brevity in code samples. Production Go code should check every err. The generator skips error handling so you see the request shape clearly; add err checks before shipping. Same for Python and JS — wrap in try/except or .catch as your conventions dictate.

Can I generate code for languages other than these five?

Specway's generator covers ~95% of the queries. For Ruby, PHP, Rust, Java, Swift, etc., use the Specway docs platform — it auto-generates code samples in 30+ languages from your OpenAPI spec, kept in sync with every API change.

How do I convert a curl command to JavaScript fetch?

Paste the curl command. Specway parses the URL, method, headers, and body, then generates equivalent code in your chosen language. Switch between JS fetch, Node fetch, Axios, Python requests, and Go net/http with one click. Copy the result and paste into your code.

Which curl options are supported?

The big ones: -X (method), -H (header), -d / --data / --data-raw / --data-binary (body), -u (basic auth), --request, --header. Less common flags (--insecure, --cert, --output, --form for multipart) are ignored — convert those manually because the equivalents differ across languages.

Why does my converted Python code fail?

Three usual causes: (1) the curl used POST without -d but the Python output assumes JSON body — set the right body type. (2) the URL has query params with characters Python's requests library encodes differently — pass params= dict instead. (3) authentication uses cookies that curl picked up from --cookie-jar — re-implement explicitly with requests.Session.

What's the difference between fetch, node-fetch, and axios?

fetch is the browser/Bun/Deno/Node 18+ standard. node-fetch is the legacy library for Node <18 (no longer needed in 2026 unless you support old runtimes). Axios is third-party, has nicer ergonomics for body/headers and built-in JSON handling. Pick fetch for modern Node, axios if your team prefers its DX.

Does the converter handle multipart form-data?

Not yet — multipart with curl's --form flag has language-specific equivalents (FormData in JS, requests.post(files=) in Python, multipart.NewWriter in Go) that vary in subtle ways. For now, use plain JSON or url-encoded bodies. We'll add multipart support if there's demand.

Why does the generated Go code do nothing with errors?

For brevity in code samples. Production Go code should check every err. The generator skips error handling so you see the request shape clearly; add err checks before shipping. Same for Python and JS — wrap in try/except or .catch as your conventions dictate.

Can I generate code for languages other than these five?

Specway's generator covers ~95% of the queries. For Ruby, PHP, Rust, Java, Swift, etc., use the Specway docs platform — it auto-generates code samples in 30+ languages from your OpenAPI spec, kept in sync with every API change.

Free Tool

cURL → Code (2026)

Convert any curl command into JavaScript fetch, Node fetch, Axios, Python requests, or Go net/http. Paste, pick a language, copy. Pure browser, no upload.

curl command

const res = await fetch('https://api.specway.com/v1/specs', {
  method: 'POST',
  headers: {
    "Authorization": "Bearer sk_test_123",
    "Content-Type": "application/json"
  },
  body: "{\"name\":\"Pet Store\",\"openapiUrl\":\"https://example.com/openapi.yaml\"}",
});
const data = await res.json();

When you reach for this

A teammate sends you a curl in Slack: "hit this endpoint and you'll see the bug." You need that same call in your test suite, your script, your documentation. Paste, pick the language, copy.

Or: API docs only have curl examples and you want something more idiomatic for your codebase. Same workflow.

What gets converted

URL — the first non-flag positional argument.
Method — from -X / --request, defaults to GET (or POST if a body is present).
Headers — every -H / --header becomes a key/value entry.
Body — -d, --data, --data-raw, and --data-binary all work. JSON is preserved as-is.
Basic auth — -u user:pass converts to a base64 Authorization header.

Edge cases the converter punts on

--form / multipart: language idioms differ (FormData vs files= vs multipart.NewWriter) — convert manually.
--cookie / cookie jars: state management differs across libraries.
--cert / --insecure: TLS handling belongs to your HTTP client config, not the request itself.
--output / file streaming: response streaming is library-specific.

For full code samples in 30+ languages

Specway's docs platform auto-generates code samples in JavaScript, TypeScript, Python, Ruby, PHP, Go, Rust, Java, Kotlin, Swift, C#, and more — for every operation in your OpenAPI spec, kept in sync with every API change. This tool is the quick one-off; Specway is the system.

Ship API docs that stay this clean

Specway turns your OpenAPI spec into a branded developer portal — auto-synced, searchable, with built-in playground and code samples in every language. Free tier available.

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Frequently asked questions