I’m having trouble getting headless browsers to work properly in JMeter. I’ve been trying different driver options but keep running into issues.
The HtmlUnit driver starts up fine, but it won’t execute any JavaScript code on the pages I’m testing. When I switch to Chrome or PhantomJS drivers, I get this error message:
java.lang.IllegalArgumentException: Browser has not been configured. Please ensure at least 1 WebDriverConfig is created for a ThreadGroup.
I’ve double checked my configuration settings for both PhantomJS and Chrome drivers, and the file paths are definitely correct. The executables are in the right locations and accessible.
What am I missing in my setup? Do I need to add some additional configuration steps to make the WebDriver work with these headless browsers? Any help would be appreciated since I need JavaScript support for my test scenarios.
It seems like you’re encountering a common issue with thread configuration in JMeter when using WebDrivers. I had similar problems with the Chrome headless setup. Make sure your WebDriverConfig is placed directly inside the Thread Group rather than nested under any samplers or controllers. This will allow JMeter to properly manage the WebDriver instances across multiple threads. Additionally, ensure that the config name aligns exactly with your WebDriver sampler. If using Chrome headless, including --no-sandbox and --disable-dev-shm-usage flags may also help improve compatibility, particularly in containerized environments, and provide better JavaScript execution. Given that PhantomJS is no longer actively maintained, transitioning to Chrome headless would definitely provide you with more reliable support for your testing scenarios.
This WebDriverConfig error happens when JMeter can’t initialize the browser driver for your thread group. I hit the same thing last year moving from HtmlUnit to Chrome headless. You need to add a WebDriver Config element at the Thread Group level - don’t just configure the sampler. For Chrome headless, set up both the WebDriver Config component and add chrome options like --headless and --disable-gpu in the arguments field. Make sure your ChromeDriver version matches your Chrome install - version mismatches will break initialization every time. Skip PhantomJS completely. It’s deprecated and causes more problems than it solves. Try Firefox headless if Chrome keeps giving you trouble. Just make sure the WebDriver Config is at the right spot in your test plan hierarchy.
that error usually means the webdriver config isn’t set right with the thread group. double-check the name in your config element matches your webdriver sampler name exactly, caps matter! also, drop any phantomjs references since it’s outdated. chrome headless should work fine after that.