SOAP vs REST is a comparison that many programmers or even software architects usually ask themselves when developing APIs for their systems, but what is really the difference between them? Is it that one is superior to the other? Could it be that REST came to replace SOAP? Well, in this article we will try to solve this great doubt.
SOAP, acronym for Simple Object Access Protocol, has been for many years the dominant focus in Service Oriented Architecture (SOA) for many organizations. It became the preferred protocol to achieve interoperability between applications.
However, its expansion has been delayed by a second alternative of distributed computing called REST (Representational State Transfer) that although it exists since the HTTP protocol appeared (that is, by the year 1991), has taken much relevance in the last decade, being used in almost 70% of public API’s.
But which is better? What communication protocol should I use? To answer them, you have to understand how each of them works and what characteristics differentiate them.
SOAP is a mature protocol with a complete and complex specification, capable of providing solutions to almost any need as far as communications are concerned.
It has been designed to expose individual operations called web services. One of the reasons why SOAP is still valid in many companies is because it provides communication support for legacy systems of an organization.
- SOAP is a good alternative for applications that require communicating through contracts for its API and the consumer, since it can impose the use of formal contracts through the use of WSDL (Web Service Description Language).
- Security is another of the strengths of SOAP services. The WS-RM or Web Service Reliable Messaging describes a protocol that allows SOAP to increase security in the execution and asynchronous processing of messages.
- SOAP works with state operations. SOAP has been designed to support state management in communication.
REST is an easy-to-understand software architecture style, supported on the HTTP protocol and its basic maintenance methods, allowing it to be easy to encode and document applications using REST services.
In addition, REST makes efficient use of bandwidth, since it is much lighter than using SOAP. Unlike SOAP, REST does not store the state and readings to its services can be cached to improve performance and scalability.
It supports many data formats to exchange information but the predominant format for web browsers is usually JSON.
REST focuses on resource-based operations, inheriting HTTP operations (GET, PUT, UPDATE, DELETE, POST). This makes many web application developers and browsers feel familiar with REST.
The simplicity offered by REST is one of the strongest reasons why large companies such as Google, Facebook and Amazon are moving their SOAP APIs to RESTFul APIs.
It is widely used in applications that require a high number of round-trip messages, in addition to applications that for some reason fail to respond, this is where REST allows to activate its re-attempt process.
REST allows easy and fast calls through a URL.
If you want to know more or understand what an api is, you may be interested in this article that I wrote about it: