Hi everyone, I’m really struggling here. I have a test suite with about 50 test cases, and right now it takes almost 2 hours to finish running. I’m trying to speed things up by running the tests across Chrome, Firefox, and Edge all at the exact same time, but I can’t figure out how to make it happen.
Here is what I’ve tried so far:
I opened my Test Suite and clicked the dropdown next to the “Run” button, but it only lets me select one browser at a time (like Chrome). If I click Firefox next, it just stops the first one or opens a completely new, separate run window.
I looked into the Execution Profile, but that seems to only change variables, not the actual browser targets.
I keep reading online that parallel execution is possible, but I am totally lost on where the setting is. How do I get Katalon to just launch all three browsers together and handle this automatically? Any step-by-step help would be amazing.
Use Test Suite Collections — this is the feature in Katalon Studio that enables parallel execution across multiple browsers. The key is adding the same test suite multiple times and setting different browsers for each.
Step-by-Step: Parallel Execution Setup
Step 1: Create a Test Suite Collection
Right-click Test Suites → New → Test Suite Collection
Name it (e.g., Chrome-Firefox-Edge-Parallel)
Step 2: Add the Same Test Suite Multiple Times
Add your test suite 3 times (once for each browser):
Test Suite Collection ├── Test Suite (for Chrome) ├── Test Suite (for Firefox) ├── Test Suite (for Edge)
Step 3: Set Different Browsers for Each
Look for the “Run with” column in the Test Suite Collection
Double-click each row in that column
Select your browser:
First row → Chrome
Second row → Firefox
Third row → Edge
Step 4: Set Execution Mode to Parallel
In Execution Information section, select “Parallel” as execution mode
Set max concurrent instances to 3 (matching your 3 browsers)
Step 5: Execute
Click Execute to run all three browsers simultaneously
Visual Setup
Test Suite Collection (Chrome-Firefox-Edge-Parallel) ┌──────────────────┬─────────────────┬──────────────┐ │ Test Suite │ Run with │ Execution │ ├──────────────────┼─────────────────┼──────────────┤ │ Your 50-TC Suite │ Chrome │ Parallel │ │ Your 50-TC Suite │ Firefox │ Concurrent: 3│ │ Your 50-TC Suite │ Edge │ │ └──────────────────┴─────────────────┴──────────────┘ ↓ [Execute] → All 3 browsers launch together
Why This Solves Your Problem
Your Issue
Solution
Dropdown only shows one browser
Test Suite Collection has “Run with” column for each suite
Running Firefox stops Chrome
Parallel mode runs all simultaneously
Can’t find parallel setting
It’s in Execution Information section of the collection
Expected Time Savings
With 50 test cases taking 2 hours:
Sequential (one browser): 2 hours × 3 = 6 hours
Parallel (3 browsers): ~2 hours (tests split across browsers)
Note: This runs in Katalon Studio UI. For cloud-based parallel execution across more environments, you can use Katalon TestCloud with Cloud Hosted environments.
The reason you cannot run multiple browsers simultaneously from a standard Test Suite is that by design, a Test Suite in Katalon Studio is a sequential collection of test cases bound to a single execution environment.
To achieve true parallel execution across multiple browsers, you must use a Test Suite Collection. A Test Suite Collection allows you to group multiple Test Suites together, assign a different environment (browser) to each, and alter the execution mode from Sequential to Parallel.
The Solution: Multi-Browser Parallel Execution
To implement a robust, scalable parallel execution strategy, follow these steps:
Create a Test Suite Collection:
Right-click on Test Suites in the Object Repository → New → Test Suite Collection.
Add your Test Suite multiple times:
Click the Add button inside the collection window.
Add your main Test Suite three separate times to the data grid.
Assign Target Browsers:
In the Run With column, click the cell for each row and assign a different browser to each:
Row 1: Chrome
Row 2: Firefox
Row 3: Edge Chromium
Enable Parallel Mode:
At the top of the Test Suite Collection view, change the Execution Mode from Sequential to Parallel.
Set the Max Concurrent Executions to 3.
Execute:
Click the main Execute button at the top right of the Test Suite Collection canvas.
Advanced Optimization: Handling Parallel Web Drivers via Custom Keyword
When running tests in parallel, traditional sequential steps can sometimes experience race conditions (e.g., trying to use a single static driver instance across multiple threads).
While Katalon handles native parallel execution seamlessly via Test Suite Collections, you can implement a Custom Keyword to safely fetch or switch to independent browser instances dynamically if your scripts require advanced multi-driver manipulation within a single test step.
Create a New Keyword (e.g., com.architecture.WebDriverUtils) and use the following code:
Groovy
package com.architecture
import com.kms.katalon.core.annotation.Keyword
import com.kms.katalon.core.webui.driver.DriverFactory
import org.openqa.selenium.WebDriver
import com.kms.katalon.core.util.KeywordUtil
public class WebDriverUtils {
/**
* Safely retrieves the current thread's WebDriver instance and validates its status
* ensuring thread safety during heavy parallel executions.
*/
@Keyword
def static WebDriver getSafeDriver() {
try {
WebDriver driver = DriverFactory.getWebDriver()
if (driver != null) {
KeywordUtil.logInfo("Successfully retrieved thread-safe WebDriver instance: " + driver.toString())
return driver
} else {
KeywordUtil.markFailed("WebDriver instance is null for the current thread execution context.")
}
} catch (Exception e) {
KeywordUtil.markFailed("Exception occurred while fetching WebDriver: " + e.getMessage())
}
return null
}
}
Architectural Recommendations for Scaling Further
Resource Constraints: Running 3 UI browsers locally requires significant CPU and RAM. If your local machine begins to lag, consider integrating your Test Suite Collection with Katalon Runtime Engine (KRE) running inside Docker containers, or routing the execution to a cloud grid like Sauce Labs or BrowserStack using the Remote execution option in your collection grid.
Data Isolation: Ensure that your test cases do not rely on shared state or hardcoded user accounts that could conflict when executed simultaneously. Use unique data rows or dynamic text generation for concurrent runs.
use a Test Suite Collection. regular test suites can only run one browser
Right-click Test Suites, pick New > Test Suite Collection. add your test suite three times, set each to a different browser, then set Execution Mode to Parallel
hit Execute and all three browsers run at once. If your machine struggles, lower Max Concurrent or use TestCloud
You expect that the parallel execution of multiple Test Suites in a Test Suite Collection will run faster than the sequential execution, don’t you?
I would argue, the parallel execution would not help you!
On a single machine, 3 Test Suites in parallel will compete for the limited CPU. memory, network resources. Be aware, the Katalon’s process is very much resource hungry! Due to the constraints, each Test Suite in parallel will run far slower than in the sequential mode. The total test duration will result similar — the parallel execution would ran the same (slowly) as the sequential execution.
As @Monty_Bagati wrote, For Test Cloud Parallel Execution which would distribute the processing workload onto multiple machines, You need to have valid license for parallel execution on test cloud. Also number of parallel execution = number of licenses. I personally don’t have the license; I haven’t tried it.
In my humble opinion, you should not hope that the parallelism will make test execution faster auto-magically. Rather, you should make continuous efforts to improve your Test Case scripts so that they run faster.
How to make your test cases faster? ---- Well, that is one of the biggest questions in Katalon Studio. There are quite a lot of factors to look into. There must be many tips to try. But I can not give you any quick take-away here, as you have not disclosed your project at all.
As per my experience, Running test collection in parallel mode is a suffering. Not because Katalon doesn’t support, but because multiple issues like network, resource constraint, handling multiple times app login, memory, and many more.
Better schedule test in the sequential at nighttime and get result in the morning and why to wait for 2 hrs
Which version of Katalon Studio with GUI do you use? If you use v10.x or older one, try upgrading to v11.0 or newer. With v11.x, your test will run much faster.
Why I say so? See the following post:
This is an example tip that affects test duration. As I wrote above, there could be a lot more points to try.
