WebdriverIO vs Behat comparison of testing frameworks
What are the differences between WebdriverIO and Behat?

	WebdriverIO https://webdriver.io/	Behat https://docs.behat.org/en/latest/
Programming language	JavaScript	PHP
Category	Browser Automation, Unit Testing, Functional Testing	Functional/Acceptance Testing
General info	WebdriverIO is the next-gen WebDriver test framework for Node.js made upon Selenium WebdriverIO is written in JavaScript and uses Selenium under the hood. It also comes with its own inbuilt test runner and supports other testing frameworks like Jasmine, Cucumber, and Mocha	Behat is an open source Behavior-Driven Development framework for PHP. Behat uses the StoryBDD subtype of behaviour-driven development (the other subtype is SpecBDD); This means the tests we write with Behat look rather like stories than code. It is inspired by Ruby's Cucumber
xUnit Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.	Yes	No
Client-side Allows testing code execution on the client, such as a web browser	Yes WebdriverIO allows the use of advanced CSS selectors and makes it easy to find elements for front-end testing	Yes To enable Behat to test a website, you need to add Mink and a browser emulator (selenium maybe, though slow) to the mix. Mink methods are the connector between Behat and an extensive list of available drivers, and they provide a consistent testing API.
Server-side Allows testing the bahovior of a server-side code	Yes It can be used to test server side behaviour and functionality	Yes Behat can be used for Data Integrity Testing to verify that database operations are functioning properly
Fixtures Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test	Yes WebdriverIO supports the creation of fixtures	Yes One can use the 'Doctrinefixturesbundle' to create the required fixture loaders and load them in our Behat scenarios when required, using the 'BeforeScenario' hook.
Group fixtures Allows defining a fixed, specific states of data for a group of tests (group-fixtures). This ensures specific environment for a given group of tests.	Yes WebdriverIO supports the creation of group fixtures	Yes Behat allows for group fixtures
Generators Supports data generators for tests. Data generators generate input data for test. The test is then run for each input data produced in this way.	N/A	By use of third party libraries like moodle-behat-generators
Licence Licence type governing the use and redistribution of the software	MIT License	MIT License
Mocks Mocks are objects that simulate the behavior of real objects. Using mocks allows testing some part of the code in isolation (with other parts mocked when needed)	Yes It contains a mocking service called 'wdio-wiremock-service'	By using third party libraries like Mock and Prophecy
Grouping Allows organizing tests in groups	Yes WebdriverIO allows one to build test suites, you can run these test in parallel and organize them by adjusting the 'maxInstances' property in your config file	Yes You can use tags to group features and scenarios together, independent of your file and directory structure
Other Other useful information about the testing framework