rest vs soap

REST Vs. SOAP: What Is The Difference will be described in this article. The acronym for application programming interface is called an API. APIs provide guidelines for the programmatic interaction and communication between various software components.

Web applications (including websites) submit queries to Web APIs, or web services, to obtain data to show to the user. A Web API is a typical sort of API. Imagine a website that takes your search parameters and provides the “best deals” for travel, lodging, or vehicle rentals. This information is not retrieved from the database by this website. Rather, it sends calls to APIs that specialise in travel, lodging, etc. to retrieve data. An API that employs the HTTP protocol to transmit data is referred to as a “Web” API.

REST Vs. SOAP What Is The Difference? Best Guide

In this article, you can know about REST Vs. SOAP here are the details below;

The ideal architectural style upon which to base an API is a topic of discussion. Although these are both criteria, a “apples to apples” comparison is not possible. The subtle difference is that SOAP is a web service access protocol, whereas REST is an architectural style for APIs. Despite their seeming rivalry, they each have unique use cases.

The distinctions between these two criteria and when to apply one over the other will be discussed in this article.

REST and SOAP: Similarities and Differences

What then is the shared characteristic between REST and SOAP, and why are they compared so often? The REST and SOAP protocols offer guidelines for clients to use when interacting with web services and the features they make available. As previously stated, SOAP is a data transmission protocol and REST is an architectural approach for APIs.

The design of a web API is subject to some limitations due to the REST architectural style. Web APIs that are deemed “RESTful” under the REST standards must follow certain REST limitations. These limitations include, among others, cacheability, statelessness, and severing the client from the API server.

The web API protocol known as SOAP establishes the format, communication protocol, and processing model for messages. It also specifies how messages must be sent. REST does not define the message processing method like SOAP does.

A REST API can use the SOAP protocol as its standard for data transmission because it is simply a web API protocol. REST and SOAP, however, are distinct protocols that are typically not combined.

Both offer standards for API message formats, however one is an architecture and the other a protocol. Both machine- and human-readable communication formats are used in REST and SOAP. JSON is a lightweight, highly browser-compatible data transfer format for REST. XML is an extended markup language for SOAP that enables the creation of unique descriptive tags for simple readability. We go into greater detail about these data formats later.

SOAP before REST

REST comes after SOAP. The purpose of REST’s design was to solve some of SOAP’s problems. REST was designed to be lightweight, work with a wide range of browsers, isolate the client from the server, and enable caching.

Given that REST supersedes SOAP and fixes its shortcomings, why is SOAP still in use?

Even though REST was designed to supplant SOAP and has several advantages over it, SOAP still has its uses. For enterprise-level systems that need message-level security, for instance, SOAP makes sense.

What is a REST API?

Representational State Transfer, or REST, is an architectural style that imposes constraints on APIs deemed “RESTful.” The following features are necessary for RESTful APIs: 1) uniform interface; 2) statelessness; 3) cacheability; 4) client-server separation; 5) layered architecture; and 6) “code on demand.” REST APIs are online applications that use the HTTP protocol. A client requests data over HTTP to an API server, which responds with an HTTP response that contains the data encoded and sent back to the client.

“Resources” are the means by which clients use REST APIs to access and modify data. Resource URLs are used to access resources, which stand for various API functionalities. Consider a resource to be a data object that the API has returned. A method blending to a CRUD (Create, Read, Update, & Delete) operation is passed to the resource when sending a request. Think of methods as “actions” that are performed on resources, such as adding, modifying, or removing resources.

For instance, the popular Swagger Petstore API has multiple resources. Pet, Store, and User are some of these resources. While they are all related to the main idea of a pet store, they individually stand for the various data elements that you can add, edit, or remove.

Sending an HTTP request with the action (method) to be performed on the resource, along with its unique URL, is how you request a resource. A few examples of actions are POST, PUT, GET, and DEL, which stand for creating, modifying, obtaining, and deleting resources, respectively.)

Advantages of REST API

Client-Server Separation

The following advantages come from separating the client from the server components:

compatibility with every component. The UI is cross-platform portable since it is decoupled from the server. Because of the “multi-layered” nature of REST architecture, the server components are portable. Because REST APIs are platform-neutral, testing during development is made simple.

limits how architectural layers interact to increase scalability (multi-layered architecture). This limitation makes server components simpler. Additionally, this architecture makes it easier to swiftly implement new updates and move data between servers.

simpler incorporation. Instead of concentrating on the server parts and data management that the API Server handles, REST enables developers to concentrate more on the user interface, functionality, and business rules.

Supports JSON Message Format

JSON is used by REST as a data format, which offers various benefits:

  • Browser Compatibility: JSON is a more browser-friendly data format that is highly compatible with most browsers.
  • Less Bandwidth Needed: JSON is a very small and simple to understand data format. When it comes to SOAP, XML payloads are bigger than JSON payloads. More bandwidth is needed for larger payloads. The message size is influenced by the amount of code that must be written in order to create an XML SOAP request.

Message Format Flexibility

REST provides additional communication forms, such as HTML, plain text, XML, YAML, and more, in addition to JSON. Because of the message formats’ flexibility, REST is especially useful for public APIs.

What is SOAP?

The abbreviation for Service Object Access Protocol (SOAP) is SOAP. It is a “standards-based web assistance access protocol,” according to SmartBear. Put otherwise, it is a protocol that governs the data transmission between clients and API servers. The following is SOAP’s main goal:

  • XML is an extensible and structured messaging format used by SOAP.
  • Many communication protocols, including HTTP, SMTP, TCP, and others, are used by SOAP.
  • The web API’s implementation language has no bearing on SOAP.

XML is used by SOAP as its data format. Extensible Markup Language is known as XML. As stated by Mozilla:

Equivalent to HTML, XML is a markup vocabulary that does not have any predefined tags. Rather, you create tags that are tailored to your requirements.

Unlike HTML, which uses predefined tags, XML allows you to store and transmit information using self-descriptive tags. Because XML is standardised, it can be easily transferred across different platforms and systems. The message format XML is highly configurable. To make sure XML payloads are compatible, you can establish XML standards that verify their structure.

Unlike REST APIs, SOAP APIs allow clients to access and modify data in numerous ways. REST enables clients to use resource URLs to obtain “data.” Conversely, SOAP entails using API “functions” to access and alter data.

No methods, or CRUD actions, are included in a request, in contrast to REST. CRUD operations are instead handled by distinct functions on the same data object. A REST API might, for instance, only have one endpoint (URL) that can be used to create or update resources by including a POST or PUT method in the request. When utilising SOAP to create or update a data object, requests for creation or updating must be sent to different functions that manage those particular CRUD processes.

XML communications are primarily sent using the HTTP or HTTPS protocols. Nonetheless, user data protocol (UDP), simple mail transport protocol (SMTP), and transmission control protocol (TCP) can all be used by SOAP APIs to transfer data. In contrast, REST is limited to supporting the HTTP protocol.

Advantage of SOAP

More secure

Because SOAP incorporates built-in ACID compliance and employs WS-Security in addition to SSL, it is a good fit for security-critical web services. REST lacks both of these characteristics. A specification for signing and encrypting SOAP XML messages is called WS-Security. Every SOAP request has a header block that contains the security information needed to fulfil the request. A set of guidelines for safeguarding a database’s integrity is known as ACID Compliance. ACID Compliance is necessary for many enterprise-level and financial transaction applications.

Flexible Transmission Channel

Multiple communication protocols are supported by SOAP. Only HTTP is supported by REST. Simple mail transport protocol (SMTP), user data protocol (UDP), transmission control protocol (TCP), and HTTP and HTTPS can all be used with SOAP.

Anatomy of REST Message

A REST message consists of the following parts:

  • Method: The CRUD action you want to take with respect to a resource. The HTTP method POST in this instance denotes the intention to produce something.
  • Endpoint: The particular URL (endpoint) to a resource. Here, is the endpoint. An object of data returned by the API that may be accessed through endpoints is called a resource.
  • Header: Indicates the message format (in this example, JSON). Similar to API keys, authorization tenants are sent in the request headers.

The JSON object in the request body has properties that can be applied to the new resource. Here, the new pet’s details are included in the request body. Request bodies are objects with numerous characteristics instead than just one, which makes them similar to parameters.

The Swagger Petstore API can be used via the REST API cURL call shown below to create a pet.

Anatomy of REST Message

Anatomy of SOAP Message

These are the “blocks” that make up a SOAP XML message:

The necessary “envelope” block designates the XML message as a SOAP communication, setting it apart from other XML messages. The namespace attribute links to the most recent SOAP version. Also check  PPC VS SEO

  • Header: An optional block that holds properties related to permission, such as API keys.
  • Body: A necessary block that details the data you anticipate getting back from the API once the request has been made. The function name (procedure) and any parameters you want to pass that will impact the outcome are listed in this block. The requested information is contained in the Body block of the response, which is the API’s answer.
  • Optional block is a fault. A SOAP API will send the error message listed here if it is unable to process the request. A request may fail for a variety of reasons. For instance, the XML schema specification can indicate that the message structure is invalid.

Let’s compare a REST message to a SOAP message in order to better grasp the SOAP message structure. The Swagger Petstore API can be used via the REST API cURL request shown below, which returns a pet by its petId. A route parameter called petId 1 is appended to the request’s resource URL at the end.


To highlight the differences, here is the SOAP counterpart of the identical request.

Below is the SOAP equivalent of the same request to show the differences

Here are a few variations:

·  Message format:

  • REST: The HTTP request is composed using the cURL programming language. REST queries, however, can be sent in any language. JSON makes up the message payload, or message body.
  • XML is the message format used by SOAP. An XML schema enforces the XML structure.

· Methods (CRUD operations):

  • REST – The request that instructs the API to retrieve something is sent with the GET method.
  • SOAP: The request contains no methods. The request is routed to the GetPet function, a retrieval method.

· Parameters:

  • REST: The pet’s ID is sent to the endpoint URL as a path parameter.
  • SOAP: The GetPet option is used in the Body block to pass the pet’s id.

See Also: Swagger API: Functions & Essential Information

When to use REST vs. SOAP

REST for public web services

The properties of SOAP and REST make them suitable for various use cases. JSON is the message format that characterises REST. Because REST uses JSON, it works well with open APIs and public web services. Compared to the XML payload used by SOAP, the JSON payload is smaller and lighter. JSON is more efficient for web browsers than XML and has a high degree of browser compatibility. Additionally, because an XML message is verbose compared to JSON, JSON payloads have considerably less characters than SOAP payloads.

It is better to use a SOAP library to make API calls from within your programming language, as SOAP XML payloads also require extra overhead to create. Although this works better, using REST does not require the additional layer of abstraction that this adds. The usage of client libraries is discouraged by REST’s restriction on client-server isolation. Web services require client-server separation in order to be scalable, portable, and autonomously evolving. You must utilise an XML parser on the client side in addition to client libraries, which adds overhead.

Resource constraints are a major problem for online services. Clients can efficiently cache HTTP answers, even though this is not directly managed by the REST API. REST uses HTTP headers to execute CRUD activities and separates endpoints using URLs, which makes caching possible.

SOAP is not the same. When submitting a payload to a SOAP API, all queries are directed to the same URL. An HTTP header for a message is always a POST header. Because POST answers are rarely cached by HTTP caches, SOAP caching is not viable or possible. The inability to provide caching for SOAP is a drawback for web service developers.

Although REST is faster and more efficient than SOAP, it does not enable message-level security. When this is necessary, an API developer might choose for REST rather than SOAP.

SOAP for enterprise applications

For online services, namely public web services, REST is the greatest option overall, however SOAP includes WS-Security built in, which REST does not. Applications that require security should use SOAP more often. SOAP has message-level security as opposed to REST.

Because of this extra security layer, enterprise-level software like CRM programmes, identity management programmes, banking applications, financial and communications services, or legacy systems are ideally suited for it.

Because SOAP is designed with ACID compliance, sensitive financial services find SOAP appealing.

Alternatives to SOAP and REST

Other than REST and SOAP, there are a few others. The most popular ones are GraphQL and GRPC.

The acronym for remote procedure call is gRPC. Microservices architectures that need lightweight messaging in settings with limited bandwidth are well suited for this standard. gRPC can be used to establish connections between Internet of Things (IoT) appliances, such as smartphones, and backend services. Also check TMetric Vs Everhour

A database query language that is gaining popularity is called GraphQL. GraphQL API data requests are more effective than REST requests. With REST, the API’s functionality is exposed over numerous (often hundreds) of distinct resource URLs. You must send queries to each resource URL if you need to obtain data from two different sources. One request can be used to query all API data when using GraphQL. Clients use filters to focus their query and retrieve data from a single API.

In Closing

Standards for how clients access and use web services and the functionality they expose are provided by the REST and SOAP specifications. On the other hand, SOAP is a protocol for sending data between a web server and a client, and REST is an architectural style for APIs. Thus, it is not “apples to apples” to compare the two.

The purpose of REST was to address SOAP’s shortcomings. Because of its advantages, REST is a good choice for public web applications with limited resources. Compared to SOAP XML payloads, the JSON data format used by REST uses less bandwidth and is highly interoperable with browsers. Additionally, REST requires client-server isolation. The effective operation of online services depends on this limitation. While SOAP is still widely used in security-sensitive settings like enterprise-level applications and financial institutions, REST has somewhat replaced SOAP for public web services.