Difference Between REST API and SOAP API

Data exchange between apps is vital in the modern world. Since applications are created in various languages, exchanging data has become complex. Web Services are the standard communication protocol for client-server applications on the Internet.

When machines need to share data and interact, they need precise formatting for certain data kinds. This is where SOAP API and REST API enter the picture. Each allows for communication and data transmission, although they vary in various aspects. From implementation to necessary resources, several characteristics distinguish between the two.

Before delving into the difference between REST API and SOAP API, let's examine their definitions and characteristics.

What is REST API?

REST (Representational State Transfer) is a communication-oriented architectural technique used often in creating online services. It is a client-server paradigm without a state. Web services that adhere to the REST architecture are RESTful web services. When a client makes a request using a RESTful API, it sends the server a representation of the resource's current state. This information may be delivered through HTTP in various forms, including JSON, HTML, XLT, and plain text, but the most used format is JSON since it is easily readable by both computers and people.

Features of REST API

• These online services are quick because they use less bandwidth and resources.
• REST is compatible with all programming languages.
• These services are compatible with any platform.
• It is a REST-based service that is both lightweight and scalable.

Advantages of REST API

• One of the primary advantages of REST APIs is that they depend on the HTTP standard, making it format-agnostic and compatible with XML, JSON, HTML, etc.
• Another advantage of REST APIs is the independence of the client and server.
• It is adaptable and scalable.

Disadvantages of REST API

• REST APIs can be tightly coupled to the implementation of the service, making it difficult to change the service without breaking client applications.
• REST APIs are stateless, which means that they do not store any information about previous requests. This can make it difficult to implement certain features, such as maintaining a user's session or implementing undo/redo functionality.
• REST APIs can be slower than other types of APIs, such as gRPC, due to the overhead of transmitting data over HTTP.

What is SOAP API?

SOAP (Simple Object Access Standard) is an XML-based protocol for gaining HTTP access to online services. It is designed as an intermediate language so applications written in different programming languages can successfully interact. SOAP is used to transport XML data between programs using Web services. Both stateful and stateless activities are supported by SOAP. Stateful indicates that the server retains the data received from the client across successive requests. These requests are chained together so the server knows the previous requests. Examples include bank transactions and travel reservations. Stateless messaging contains sufficient information about the client's status, so the server need not be concerned.

Features:

• SOAP is an XML-based protocol with XML data layout, making it simple for programmers to comprehend.
• It is a protocol independent of the platform.
• It is an open protocol standard; therefore, anybody may use it.
• It is an HTTP protocol extension for XML communications.

Advantages:

• Independent of language, platform, and conveyance.
• Works effectively in dispersed corporate setups.

Disadvantages:

• SOAP APIs can be complex to use, particularly for developers who are new to web services. They require a thorough understanding of XML and often involve creating and parsing complex messages.
• SOAP APIs can be tightly coupled to the implementation of the service, making it difficult to change the service without breaking client applications.
• SOAP APIs are vulnerable to certain types of attacks, such as XML injection and denial of service (DoS), which can compromise the security of client applications.

REST API vs. SOAP API

Conclusion

SOAP and REST are the two most prevalent web services. Both have their own significance in certain situations. Based on our needs and the program's complexity, we must choose one. REST is easier to design, but SOAP gives more possibilities, making it significantly more harder to develop.

Related Questions

1. Why REST API is faster than SOAP?

REST is faster than SOAP because of the involvement of JSON (which is light-weight) in the request/payload of REST. Each method is processed independently in REST which is the reason why it is called “stateless” architecture.

2. Is SOAP stateful or stateless?

SOAP is by default stateless, but it is possible to make this API stateful. It is stateful, i.e. no server-side sessions occur. It is data-driven, meaning that data is available as resources. It has WS-security (Enterprise-level security) with SSL support.

3. Can SOAP use JSON?

SOAP can use JSON for communication, but the reverse is not at all possible. SOAP uses XML format, whereas JSON uses a key-value pair. The error message can be declared with SOAP, but the same is not possible with JSON.

4. Which is safer SOAP or REST?

While REST is faster than SOAP and makes things easier, we have to admit that SOAP is more secure. Both SOAP and REST can use SSL or Secured Socket Layer for protecting the data during the API call request. However, SOAP goes an extra mile and supports Web Services Security as well.