Multiple applications communicate and share data through APIs, which outline the rules for their interaction. Developers consider SOAP and REST approaches when designing APIs to determine the best fit for their needs. SOAP is known for its security and uses XML format, while REST is known for being responsive, flexible, and enabling data exchange in various formats.
Although both REST and SOAP have similarities
- Describes rules and standards on how applications can create, process, and respond to data requests from other applications.
- Uses the standardized internet protocol – HTTP to exchange information.
- Supports SSL/TLS for secure and encrypted communication.
Key differences between SOAP and REST
Simple Object Access Protocol (SOAP)
- Is a protocol to communicate with applications
- API design exposes the operation
- Supports XML only to exchange data
- Performs slower communication because of the large messages in nature
- It is difficult to scale as the server maintains its state by storing the history of messages exchanged with the client
- Supports encryption with additional overheads
REpresentational State Transfer (REST)
- Is an architectural style used to design a communication interface
- API design exposes the data
- Supports XML, JSON, plain text, and HTML
- Performs faster communication because of smaller messages and supports caching
- It is scalable as it is stateless, so every message is processed independently of previous messages
- Supports encryption without affecting performance
Making the Right API Design Choice
When choosing between SOAP and REST, it’s crucial to assess both your specific use case and the needs of your API consumers. Here are some key factors to take into account:
Application Architecture
For modern systems like mobile or hybrid apps, REST APIs are often the preferred choice due to their scalability and flexibility. REST supports contemporary architectural patterns such as microservices and containerization. However, if you’re working with legacy systems that rely on existing SOAP APIs, it might be more efficient to stick with SOAP for integration and extension purposes.
Security Considerations
Public APIs are generally open and require broader accessibility, making REST a better fit due to its flexibility. On the other hand, private enterprise APIs, especially those dealing with sensitive data such as financial transactions, may benefit from SOAP because of more robust security standards, providing enhanced protection.
Atomicity, Consistency, Isolation, Durability (ACID) Compliance
If your application requires strict consistency and integrity for transactions such as in financial services, where every part of a transaction must succeed or fail as a unit, SOAP is more suitable. SOAP natively supports ACID properties. Whereas, achieving this level of transactional integrity with REST may require additional configurations at the server or database level.