Expert's Practical Guide of API Testing using Postman-2026

Learn prerequisites for API testing with Postman, covering web services basics, SOAP versus REST, HTTP methods like GET, POST, PUT, DELETE, and JSON data exchange.

Explore microservices architecture and how it compares to monolithic design, showing how independent module deployment reduces downtime while testing rest APIs for each service.

Learn rest api testing basics using postman, including get, post, put, delete, patch, head, options, and trace to fetch, add, update, or delete data, with headers and body concepts.

Discover JSON, a lightweight JavaScript object notation for data exchange. Build data as key-value pairs, arrays, and nested objects like address and phone to send requests between client and server.

Explore json path basics to fetch and validate json keys and values with adjacent and contains operators, navigate to specific fields, and verify data in responses.

Start by sending a basic get request in Postman to fetch a single student’s data and then fetch all students, verifying the 200 status at each step.

Add automated Postman validations for status codes, response times, and response body data using the test section and code snippets, across post, get, put, and delete requests.

Learn to validate response headers in Postman, including ensuring headers like content type and server exist and contain expected values, alongside status code string checks.

Learn how collections in Postman function as containers to save and organize requests, enabling multi-step test suites, folders, and regression testing with single-click execution and team sharing.

Save requests to collections by organizing them into folders and test cases, such as adding, updating, fetching, validating, and deleting a student, plus negative tests and assertions.

Harness the Postman collection runner to execute an entire collection in order with a single click, view per-request assertions and a summary report, and run iterations or targeted folders.

Learn how environments in Postman let you manage different involvement data (dev, UAT, production) without editing every request. Use environment-specific usernames, passwords, and data to run tests quickly and accurately.

Set up environments and reuse environment data in test cases by defining variables such as API base URL, username, and password, then reference them with double curly braces.

Learn how to implement request chaining (correlation) in Postman to extract data from a response and use it as input in subsequent requests, enabling automated collection execution.

Explore using the Postman request object to fetch the body, method, and other properties, noting that the request is read-only, while performing a post request to a local server.

Learn to use the Postman response body object to fetch and parse JSON from a server response, extracting title and id in the test script after a POST.

Learn to manage Postman environment variables by coding, including setting, retrieving, displaying, and clearing enrollment variables with pre-request scripts and the Postman object, plus console output.

Set and fetch global variables in Postman via the pre-request script. Clear single or all global variables to control data flow across requests.

Learn to chain requests in postman by extracting data from a response and using that data as input for subsequent requests, storing values in global variables for seamless multi-step testing.

Learn how to apply basic authorization in Postman by passing username and password in the request, and use global variables to secure credentials when accessing protected APIs such as GitHub.