What is the difference between SOAP and REST?

SOAP is a strict XML-based protocol with a formal contract (WSDL), built-in error handling, and support for WS-Security. REST is an architectural style using plain HTTP and JSON, lighter and easier to use but without a formal contract standard.

What does the SOAP Header contain?

The Header carries metadata like authentication tokens, message IDs, routing instructions, or transaction context. It is processed by intermediaries or the endpoint before the Body is acted on.

How do I test a SOAP endpoint?

Use curl with a Content-Type: application/soap+xml header and the envelope as the POST body, or use tools like SoapUI or Postman (which supports SOAP requests). The XML formatter helps prepare the envelope before sending.

SOAP Request Envelope XML

SOAP (Simple Object Access Protocol) is the XML-based messaging format used by enterprise web services, financial systems, and legacy enterprise APIs that predate REST. A SOAP message consists of an Envelope containing an optional Header for authentication or routing, and a Body with the actual request or response payload. The XML formatter validates the SOAP namespace declarations and element structure required for interoperability. When integrating with SOAP services, paste the WSDL-defined request structure here to format and review it before sending with curl or a SOAP client.

Example

<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope
    xmlns:soapenv="http://www.w3.org/2003/05/soap-envelope"
    xmlns:web="http://webservice.example.com/">
  <soapenv:Header>
    <web:AuthHeader>
      <web:Username>apiuser</web:Username>
      <web:APIKey>abc123xyz</web:APIKey>
    </web:AuthHeader>
  </soapenv:Header>
  <soapenv:Body>
    <web:GetUserDetails>
      <web:UserId>12345</web:UserId>
      <web:IncludeAddress>true</web:IncludeAddress>
    </web:GetUserDetails>
  </soapenv:Body>
</soapenv:Envelope>

[ open in XML Formatter → ]

FAQ

What is the difference between SOAP and REST?: SOAP is a strict XML-based protocol with a formal contract (WSDL), built-in error handling, and support for WS-Security. REST is an architectural style using plain HTTP and JSON, lighter and easier to use but without a formal contract standard.
What does the SOAP Header contain?: The Header carries metadata like authentication tokens, message IDs, routing instructions, or transaction context. It is processed by intermediaries or the endpoint before the Body is acted on.
How do I test a SOAP endpoint?: Use curl with a Content-Type: application/soap+xml header and the envelope as the POST body, or use tools like SoapUI or Postman (which supports SOAP requests). The XML formatter helps prepare the envelope before sending.

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