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

Selenium

https://pypi.org/project/selenium/

WebdriverIO

https://webdriver.io/
Programming language

Python

JavaScript

Category

Web Automation

Browser Automation, Unit Testing, Functional Testing

General info

Selenium is an open source tool used to test web applications

Selenium is a powerful testing tool which can send standard Python commands to different browsers, despite variations in browser design. It also provides extensions to emulate user interaction with browsers, a distribution server for scaling browser allocation, and the infrastructure for implementations of the W3C WebDriver specification that lets you write interchangeable code for all major web browsers

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
xUnit
Set of frameworks originating from SUnit (Smalltalk's testing framework). They share similar structure and functionality.

No

Yes

Client-side
Allows testing code execution on the client, such as a web browser

Yes

It is primarily a browser automation tool which tests front-end components and functionality

Yes

WebdriverIO allows the use of advanced CSS selectors and makes it easy to find elements for front-end testing
Server-side
Allows testing the bahovior of a server-side code

Yes

It can perform Unit tests and can test various components and behaviours in the backend using a BDD or TDD approach

Yes

It can be used to test server side behaviour and functionality
Fixtures
Allows defining a fixed, specific states of data (fixtures) that are test-local. This ensures specific environment for a single test

Yes

By writing your Selenium WebDriver tests in PyTest, this gives you access to Pytest's powerful fixture model

Yes

WebdriverIO supports the creation of fixtures
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

One can group fixtures if accessing Pytest's fixture model

Yes

WebdriverIO supports the creation of 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.

Yes

By using a library such as Faker or Fake-factory

N/A

Licence
Licence type governing the use and redistribution of the software

Apache License 2.0

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 includes support for mocking

Yes

It contains a mocking service called 'wdio-wiremock-service'
Grouping
Allows organizing tests in groups

Yes

By using the TestNG feature with which we can create groups and maintain them easily

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
Other
Other useful information about the testing framework