SOAP vs REST: Key Differences Explained

SOAP and REST represent fundamentally different approaches to web service communication, with SOAP being a formal protocol and REST an architectural style. REST indeed offers advantages in flexibility by supporting multiple data formats (JSON, XML, HTML, plain text) and eliminating the need for UDDI service discovery, while SOAP provides stronger standardization and more comprehensive security options for enterprise environments.

Contents

• Fundamental Differences Between SOAP and REST
• REST Advantages in Dynamic Nature and UDDI Independence
• Data Format Support: REST vs SOAP
• Standardization and Security Comparisons
• When to Choose SOAP vs REST
• Practical Implementation Examples

Fundamental Differences Between SOAP and REST

The core distinction between SOAP and REST lies in their fundamental nature:

• SOAP is a protocol, while REST is an architectural style according to AWS and Red Hat

• SOAP follows very strict structure and standardized contracts such as Web Service Description Language (WSDL), while REST is more flexible and uses standardized HTTP methods

• SOAP clients work like custom desktop applications, tightly coupled to the server with rigid contracts between client and server, while REST clients are more like browsers - generic clients that know how to use a protocol and standardized methods

SOAP provides the following advantages when compared to REST: Language, platform, and transport independent (REST requires use of HTTP), works well in distributed enterprise environments (REST assumes direct point-to-point communication), and is standardized with formal protocols maintained by the World Wide Web Consortium (W3C) source:Smartbear

REST Advantages in Dynamic Nature and UDDI Independence

The claim about REST being more dynamic and not requiring UDDI is accurate based on the research findings:

• UDDI (Universal Description, Discovery, and Integration) was designed specifically for SOAP-based web services and is essentially “dead as of 2006” according to Stack Overflow

• REST eliminates the need for service registries like UDDI, operating with direct communication through standardized HTTP methods

• Multiple sources confirm that REST is more dynamic with no need to create and update UDDI registries source:Stack Overflow, as stated in the original question

• The discovery process for REST services is typically handled through conventions, documentation, or API gateways rather than centralized registries

“No UDDI registries in the REST world… this idea smacks of Opera Turbo” - ResearchGate

Data Format Support: REST vs SOAP

The assertion about REST supporting multiple data formats while SOAP is limited to XML is completely accurate:

• SOAP is strictly XML-based: “SOAP will always send data in an XML format” according to iFax

• REST supports multiple formats: “REST can send data in JSON, plain text, HTML, and more” source:iFax

• Performance benefits: REST APIs support caching and use lesser bandwidth compared to SOAP, resulting in “lesser latency and in turn, a better user experience” source:Medium

• Modern web development: REST’s format flexibility makes it particularly well-suited for mobile applications and modern web services

Standardization and Security Comparisons

Regarding standardization and security, the research shows that SOAP offers more formal standardization while both approaches have security capabilities:

SOAP Standardization Advantages

• Formal protocol maintained by W3C: Unlike REST, which is an architectural style, SOAP is an official protocol with standardized specifications

• Language, platform, and transport independence: SOAP works across different languages and platforms, while “REST requires use of HTTP” source:Smartbear

• Built-in service discovery: SOAP has standardized UDDI registries and WSDL service descriptions

Security Comparisons

• SOAP has more security options: “I wouldn’t proclaim SOAP is more secure than REST. Rather, I’ll say that SOAP has more security options to work with, which makes it ideal for enterprise applications that require fine-grained security” source:HubSpot

• Enterprise security features: SOAP includes standardized security measures like WS-Security, WS-Trust, and WS-Federation, which provide comprehensive security for distributed enterprise environments

• REST security: REST typically relies on standard HTTP security mechanisms like HTTPS, OAuth, and API keys, though it can implement additional security layers

When to Choose SOAP vs REST

Based on the research findings, here are the typical use cases for each approach:

Choose SOAP When:

• Enterprise integration requiring strict contracts and standardized communication
• Financial institutions and banking applications needing robust security
• Systems requiring ACID transactions and guaranteed delivery
• Cross-platform integration where language independence is crucial
• Applications needing fine-grained security and standardized protocols

Choose REST When:

• Modern web and mobile applications requiring flexibility
• Public APIs where ease of use and developer adoption are important
• High-performance systems where caching and bandwidth efficiency matter
• Microservices architectures requiring lightweight communication
• Applications needing multiple data formats (JSON, XML, etc.)

“Therefore, most financial institutions… Strict protocol: SOAP is a protocol with stricter standards and a more formal structure compared to REST” source:UltaHost

Practical Implementation Examples

SOAP Example (Banking Application)

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">
  <soap:Body>
    <m:Transfer xmlns:m="http://example.com/transfer">
      <m:FromAccount>12345</m:FromAccount>
      <m:ToAccount>67890</m:ToAccount>
      <m:Amount>1000.00</m:Amount>
    </m:Transfer>
  </soap:Body>
</soap:Envelope>

REST Example (E-commerce API)

GET /api/products/12345
{
  "id": 12345,
  "name": "Wireless Headphones",
  "price": 99.99,
  "category": "Electronics"
}

POST /api/orders
{
  "items": [{"product_id": 12345, "quantity": 2}],
  "total": 199.98
}

The coding of REST APIs and services is “far more seamless than SOAP” according to Wallarm, while SOAP provides the structure needed for mission-critical enterprise applications.

Conclusion

The research confirms that REST indeed has significant advantages over SOAP in being more dynamic (not requiring UDDI service discovery) and supporting multiple data formats beyond just XML. However, SOAP offers stronger standardization and more comprehensive security options for enterprise environments.

Key takeaways:

1. REST eliminates the need for UDDI registries and operates with direct HTTP communication
2. REST supports multiple data formats (JSON, XML, HTML, plain text) while SOAP is XML-only
3. SOAP provides more formal standardization as an official W3C protocol
4. SOAP offers more security options for enterprise applications
5. The choice depends on specific requirements: REST for modern web applications, SOAP for enterprise integration

For most modern web applications, REST’s flexibility and performance advantages make it the preferred choice, while SOAP remains valuable for mission-critical enterprise systems requiring strict contracts and robust security.

Sources

1. SOAP vs REST: What’s the Difference? - SmartBear
2. SOAP vs REST API protocols - Difference and Benefits - Wallarm
3. REST vs SOAP APIs: The key differences explained for beginners - HubSpot
4. SOAP vs REST API: What’s the Difference? - iFax
5. SOAP vs REST: Which Web Service Protocol is Better? - UltaHost
6. REST vs SOAP | Difference Between REST and SOAP - Stack Overflow
7. Is there an UDDI or any other registry for RESTful Webservices - Stack Overflow
8. REST vs. SOAP - Red Hat
9. SOAP vs REST API protocols - Difference and Benefits - Medium
10. SOAP vs REST - AWS