Tool description

The cURL Command Validator checks curl commands the way bash, zsh and curl itself read them, and shows what request the command sends. Paste a command, for example one from your browser's "Copy as cURL", and see the HTTP method, URL, headers, query parameters, body and authentication, along with any errors, warnings and notes pointing to the exact line and column.

Features

  • Shell checks: unclosed quotes, missing or broken backslash line continuations, unquoted & and ? in URLs, curly quotes, variables in single quotes, and Windows cmd or PowerShell syntax
  • Option checks: every curl 8 option, with suggestions for misspelled ones, missing or malformed values, and deprecated or insecure options such as -k
  • Request checks: conflicting methods (-d with -I), unneeded -X, invalid URLs, duplicate headers, JSON bodies that aren't valid JSON or are sent as a form
  • Request details: method, URL, host, HTTP version, content type, body size, authentication, redirects, TLS verification, headers curl adds on its own, and a description of every option

What is cURL?

cURL is a command-line tool for transferring data using various network protocols. It's commonly used for:

  • Making HTTP/HTTPS requests to APIs
  • Testing REST endpoints
  • Downloading files
  • Sending data to servers
  • Debugging network issues

A typical cURL command includes the URL, HTTP method, headers, authentication credentials, and request body.