The point of differences mentioned below will help you to understand which ONE is more secure and when:

• If standardization and security are the main goals, then SOAP should be considered as the stronger one to practice as the WEB Services. Also, SOAP offers WS-Security which is like an extra perk to the enterprise.
• The REST API is compatible with a number of types of data outputs including JSON, XML, CSV while SOAP is able to handle XML only. With the help of REST using JSON helps to cut down a lot on the expenses.
• REST is further advanced, therefore when the next endpoint requests one query completed beforehand, the development of API can make use of the data that too from the earlier request. Whereas, SOAP IMPLEMENTATIONS need to PROCESS all the queries each and every single time.

Although it sounds as if SOAP is more advantageous than REST, yet one good REST implementation can be really beneficial for an enterprise rather than using the poorly-designed SOAP API. And SOAP possesses in-built error handing to communicate ERRORS through the specification of WS-ReliableMessaging. Whereas, REST needs to send the transfer again every time it encounters one error.