Free tutorials and practice
About CodeKru
CodeKru helps testers and developers learn test automation: Selenium, Playwright, TestNG and API testing, plus the Java behind them. We have been writing free tutorials since 2020, and our course lessons now come with practice tasks you solve in a real browser.
- 380+free tutorials
- 314practice tasks on CodeKru Tools
What you can learn here
Selenium Java
Starts with what Selenium is and builds up, one lesson at a time, to locators, waits and stable tests. Practice tasks and walkthrough videos follow the lessons.
5 tutorialsAPI Testing
A beginner course on API requests, responses and status codes. No code needed.
17 tutorialsSelenium Python
Locators, waits and browser actions with Selenium in Python.
41 tutorialsPlaywright Java
Browser automation with the Playwright Java API, one method at a time.
40 tutorialsTestNG
Annotations, assertions, groups, data providers and parallel runs for your tests.
15 tutorialsJMeter
Performance and load testing with Apache JMeter.
125 tutorialsJava
The Java you need for automation: strings, collections, OOP, and a method-by-method reference.
New to test automation? Start here
- Learn enough Java. Variables, strings, classes and collections. The Java tutorials cover each one with a short example.
- Take the Selenium Java course. Lesson by lesson, from setting up your first test to waits that keep tests stable.
- Practice every lesson. Solve the lesson's tasks on CodeKru Tools. Stuck? Watch the task walkthrough on YouTube.
- Organise your tests. Use TestNG to group, order and run them.
How the tutorials work
Courses teach a subject in order. Each lesson uses only what earlier lessons taught, and explains every new term before it uses it.
Reference posts answer one question each, such as how one Selenium or Java method works, with a short example and its output.
Practice tasks sit at the end of course lessons. Each one opens a practice page on CodeKru Tools, where your code runs in a real browser and gets checked.
How we keep lessons accurate
Before a new course lesson goes live, we check its facts against the official documentation (Selenium, Java, Playwright) and have it read by a beginner reviewer.
When a tool changes, such as a new Selenium version, we update the lesson itself instead of writing a new post.
Found a mistake? Tell us and include the tutorial link. We fix it in the post, so every reader gets the correction.
Practice what you read
CodeKru Tools
Graded tasks for Selenium Java, Selenium Python, Playwright, REST Assured and manual API testing, plus online compilers that need no setup. Free.
YouTube
Task walkthrough videos: watch a practice task get solved step by step, at a beginner's pace.
TestKru
Practice pages with forms, tables, alerts and frames to try your own automation scripts on.
Questions or corrections?
Ask about a tutorial, report a mistake or suggest a topic. We reply by email.