How Fetch to cURL Converter Works

The converter reads your fetch() call, detects the request URL, method, headers, and body, and then formats those parts into a cURL command that you can run in macOS, Linux, or Windows terminals (including WSL). It focuses on practical, real-world fetch patterns such as JSON APIs, bearer tokens, custom headers, and POST bodies.

Step-by-Step

• 1) Paste your fetch snippet: Add the code exactly as it appears in your project (including headers and body).
• 2) Choose output preferences: Decide whether you want a single-line command or a readable multi-line command with line breaks.
• 3) Convert: The tool extracts the URL, method, headers, and payload and builds a matching curl invocation.
• 4) Copy or download: Copy the result to clipboard or download it as a text file to attach to tickets, docs, or bug reports.
• 5) Run and iterate: Execute the cURL command, compare the response with your app behavior, and adjust headers or payload as needed.

Key Features

Accurate method and URL detection

Whether your request is GET, POST, PUT, PATCH, or DELETE, the converter attempts to read the explicit method option and applies it to curl -X. It also extracts the URL from the first fetch() argument, so you do not need to retype endpoints.

Header extraction for common fetch patterns

Headers are one of the most common reasons an API call behaves differently across environments. The tool looks for headers defined as plain objects and formats them as -H flags (for example, Authorization tokens, Accept, Content-Type, custom x- headers, and tracing headers).

Body handling for JSON payloads

If your fetch body uses JSON.stringify(...), the converter will output a JSON payload in --data. When appropriate, it also helps ensure the request includes a JSON content type header so servers interpret the payload correctly.

Readable multi-line output

When you are sharing a request in documentation or code reviews, a multi-line cURL command is easier to scan. Enable multi-line formatting to place each header on its own line and keep long JSON bodies manageable.

Copy, reset, and download workflow

Built-in copy and download actions make it easy to move the generated command into Postman alternatives, CI debugging steps, or internal runbooks. Reset returns the form to a realistic example so you can test the tool instantly.

Use Cases

• API debugging: Reproduce a failing fetch() request outside the browser to isolate server-side issues.
• Backend verification: Validate required headers, authentication, and payload structure against staging or local environments.
• Sharing reproducible requests: Send a teammate a single cURL command that mirrors the exact request your frontend is making.
• Testing auth and tokens: Quickly verify bearer tokens, API keys, or custom authorization headers from the command line.
• Converting docs: Turn code snippets from README files or tickets into terminal commands for faster onboarding.
• Regression checks: Save generated cURL commands to compare responses after deployments or configuration changes.

In short, the converter helps you move between browser code and terminal workflows without losing important request details like headers and payload formatting.

Optimization Tips

Prefer explicit headers in fetch()

If you rely on implicit browser headers, your cURL command may not include them. For the most accurate conversions, define key headers explicitly (especially Authorization, Accept, and Content-Type) so the terminal request matches the app request.

Keep payloads deterministic

When possible, pass a literal object to JSON.stringify or a concrete string body. If the body is built from variables at runtime, consider temporarily logging or pasting the resolved payload so you can generate a cURL command that will run immediately.

Use multi-line mode for long requests

Large JSON bodies and many headers are easier to inspect in multi-line format. Once you confirm the request is correct, you can switch to single-line output to paste into scripts.

FAQ