QA Guide to REST API Testing for Beginners

Learn how APIs enable two systems to communicate via request and response. Compare rest, a representational state transfer architectural style, with soap protocols, and note popular APIs like Google Maps.

Explore how a client requests data from API servers through web servers, with endpoints returning data or performing functions, and how browsers can access simple APIs directly.

Explore the structure of api endpoints by breaking down a sample rest countries api, including the base path and resource path that returns data like currency, language, and calling codes.

Explore the five rest api request methods - get, post, put/patch, and delete - mapped to read, create, update, and delete (crud). See how endpoints retrieve, modify, or remove data.

Learn how http status codes communicate transaction outcomes, with 200-level successes, 400-level client errors, and 500-level server errors, including common codes like 400 bad request.

Explore headers in api testing, including request headers and response headers; learn how authorization headers enable access, how missing them triggers 401, and how status 200 appears in responses.

Explore request and response bodies in rest api testing, showing how json payloads carry data like first and last names in post or put requests and responses with 200 ok.

Learn to use Sublime Text as a fast data editor, install the package control manager, and set up the Pretty JSON package on Mac or Windows for streamlined JSON editing.

Install Sublime Text on Windows, complete a quick, light setup, and explore tabs and shortcuts. See how Sublime aids viewing and editing data.

Install package control in Sublime Text using the command palette to access package management, browse packages, and install tools like snippets, syntax support, and file comparison features.

Install pretty json to validate and format json in your editor. Use its convert and modify features to remove line breaks and consolidate into a single line for efficient loading.

Learn to validate json in your editor using a json validator, save the file to set syntax, and use highlights to locate and fix errors like misplaced commas.

Learn to format and validate JSON, using pretty print for human readability and minified versions for machine efficiency, and apply these practices to share readable data with developers.

Explore javascript and json data (javascript object notation) to understand how json relates to API testing, using the browser console for hands-on exercises and refreshing the console between tasks.

Explore data types in JavaScript, including string, number, boolean, array, and object, with examples of quotes, true/false, and keys and values.

Learn how to declare and use variables in JavaScript, including memory, case sensitivity, and data types (number, string, boolean, object), with camelCase naming, reassignment, and string concatenation.

Arrays use square brackets; store numbers, strings, booleans, or objects. Access items by zero-based indices; use length to count and get the last item (length minus one). Undefined indicates out-of-bounds.

Create javascript objects with json notation, define keys and values, include arrays and nested objects, and validate and pretty print for readability.

Learn to access object properties and array elements with dot notation and indexing, including nested objects and first array items, using practical examples from the lecture.

Learn the basics of Postman by creating api requests and viewing responses. Save and organize requests into replayable collections, with hands-on practice with methods, variables, and parameters.

Install Postman by downloading from the official site, choosing Windows, Mac OS X, or Linux, and selecting 64-bit or 32-bit; the install takes about a minute with an empty history.

Create and test api requests using Postman with the Numbers API, understanding endpoints, resources, status codes, headers, and response bodies through hands-on examples.

Organize your API requests with collections and folders, create a numbers API collection in camel case, add trivia, date, and year requests, and save or send them to verify responses.

Master path parameters in rest api testing by using colon syntax in Postman to replace values, contrast them with query parameters, and create readable, parameterized requests.

Learn how query parameters work using the ? syntax with name=value pairs, join multiple parameters with ampersands, and explore min‑max range examples and parameter requirements.

Explore post, put, and patch requests against a fake open api for testing and prototyping; learn to craft request bodies, view responses, and practice with Postman.

Master delete requests in rest api testing by specifying the item id (post, comment, or album), switching from get to delete, and expecting an ok status and empty array.

Postman variables let you reuse data across requests, using global and collection scopes, with the {{variable}} syntax, so a 56-character pin updates everywhere.

Learn how API keys control access and usage in REST APIs, obtain a free key with 1000 daily limit, configure it in Postman, and identify 401 or invalid key responses.

Explore postman's environment variables to switch between dev, qa, staging, and production by defining a base URL and referencing it with curly braces; customize dynamic values without hard coding.

Explore headers in postman, learn how to add standard headers and authorization headers, and set token values for API calls.

Learn how to test an API with Postman, run tests automatically, access the test tab for saved requests, and explore built-in snippets, docs, and scripts to implement common test scenarios.

Learn to create and run status code tests in Postman using JavaScript snippets, testing single and multiple codes (200, 400), and validating responses by code name.

Utilize postman to test rest api body content by adding tests that verify response bodies contain specific strings, including posts, user ids, titles, and escaped characters, with dynamic data validation.

Learn to use environment and global variables in REST API tests, insert them into tests with curly braces, and validate responses by string matching.

Test API response time to ensure requests complete quickly, ideally under 200 milliseconds, using console readings, and define an acceptable range with your team to keep the site snappy.

Test headers in Postman by inspecting the headers tab in the response and confirming which headers are present. Verify header values, such as content-type, and note that content-length may vary.

Build a poke api testing collection with get requests for berries and Pokemon by id and by name, and create tests for headers, body, and response time.

Practice postman testing by building berry by id and by name requests, configuring an environment base URL, and writing tests to validate status, timing, headers, and payload fields in PokeAPI.

Use browser developer tools to view internet requests and API calls from web pages. Explore demos in Chrome, Safari, and Internet Explorer to analyze REST API interactions.

Discover how to open the developer tools in Chrome and Safari. Learn to use the network tab, inspect elements, and adjust the tool layout across Windows and Mac.

Inspect browser network traffic with dev tools to view API requests and status codes like 200 or 404, and examine responses and headers to diagnose issues.

Learn to use Fiddler, a debugging proxy that captures web traffic from browsers and mobile apps. Follow a Windows-based tutorial covering setup and use, with a Mac beta.

Install fiddler by downloading the Windows installer, choose defaults, then configure http/https settings, decrypt HTTPS traffic, and trust the root certificate to view all traffic.

Explore the session window to observe web service calls, API requests, and data submissions, Google Analytics. Clear the session to reduce clutter and note browser caching with Popey API interactions.

Explore the inspectors tab to view API requests and responses, using the raw view for unformatted data, and practice saving or copying sessions to document headers and bodies with fiddler.

Customize the session data view by adding and arranging columns like session timer, client begin response, client response, and request method to monitor overall elapsed time and specific timings.

Learn to filter requests in rest api testing by applying host name filters, hiding unwanted traffic such as images, and selecting web browser versus non-browser traffic, while saving filter sets.

Learn to use the session timeline to analyze performance by selecting sessions, refreshing, and double-clicking items to view transactions, durations, and filters for identifying slow steps and optimizing load times.

Learn how to replay and reissue requests in Fiddler, including get requests, sequential replay, and verification, without using Postman or browser tools.

Simulate varying network speeds, including modem-like delays, to test how your app handles API calls on slow connections and maintains stability with caching and retry messaging.

Learn to use the auto responder in fiddler to simulate API errors by enacting rules, replaying requests, and editing status codes and responses for robust REST API testing.

Master the basics of APIs, learn JavaScript and JSON, and use Sublime Text, Postman, and Fiddler to validate, format, generate requests, and build automated API tests.