Skip to main content


  • 14 minutes to read

General Questions

I have heard that TestCafe Studio does not use Selenium. How does it operate?

Unlike most testing solutions, TestCafe Studio is not built on Selenium. This allows us to implement features you cannot find in Selenium-based tools (for example, testing remote devices without extra plugins and automatic waiting).

TestCafe Studio uses a URL rewrite proxy that allows the application to work without WebDriver. The proxy injects client-side automation scripts into the page.

What is the difference between TestCafe Studio and open-source TestCafe?
  TestCafe TestCafe Studio
No need for WebDriver, browser plugins or other tools
Cross-platform and cross-browser out of the box
Write tests in the latest JavaScript or TypeScript
Clear and flexible API supports ES6 and PageModel pattern
Stable tests due to the Smart Assertion Query Mechanism
Tests run quickly due to intelligent Automatic Waiting Mechanism and Concurrent Test Execution
Custom reporter plugins
Use third-party Node.js modules in test scripts
Integration with popular CI systems  ✓*
Visual Test Recorder  
Interactive Test Editor  
Automatic Selector Generation  
Run Configuration Manager  
IDE-like GUI  

* You can use the open-source TestCafe test runner to integrate tests with CI systems.

What is the difference between TestCafe Studio and TestCafe v2015.1?

You can find this information in our blog.

Which browsers does TestCafe Studio support? Which specific versions are supported?

You can find a list of supported browsers in our documentation. TestCafe Studio is tested against the two latest versions of each browser (except browsers whose versions are specified explicitly in this list).

However, TestCafe Studio should work properly with browsers that support HTML5 and released in the last three years.

What is the current version of TestCafe Studio? How do I update it?

To view the current version number:

  • MacOS: Open the TestCafe Studio menu and select the About command.
  • Windows and Linux: Open the Help and select the About command.

This invokes the dialog that displays version information.

The About dialog

To download the latest version, visit our site.

For Windows and MacOS: When a newer version of TestCafe Studio is available, the notification appears on the main toolbar. Click the Install link to update to this version.

Update version

I found a bug. How do I report it?

You can report a bug in our Support Center.


What is the difference between codeless tests and test scripts?
  Codeless Test Test Script
Consists of … Test actions JavaScript or TypeScript code
How do I create… Record or manually compile from action templates Record or write script code
How do I edit… * Use the recorder to add new actions to an existing test
* Add, update, and remove test actions in the Test Editor
Use the Code Editor
How do I convert to another test type… Can convert to JavaScript Cannot convert to a codeless test
File extension .testcafe .js, .ts
Can I record test scripts?

TestCafe allows you to record test scripts.

You can also create a codeless test, then convert it to JavaScript.

For more information about the difference between codeless tests and test scripts, see the previous question.

How to make sure that my test is being recorded correctly?

When you interact with a webpage during recording, TestCafe Studio automatically updates the test with corresponding actions. You can look at the editor to confirm that they are correct. For example:

  • TestCafe Studio generates a set of element selectors for a target element in a test action and adds one of them to the action parameters. Make sure that this element selector fits your needs, or select another one while recording.

    The set of element selectors

    You can also view the element that corresponds to this selector on the webpage. See Elements Highlighting.

  • While recording, you can perform some extra actions that are unnecessary for your test, for example, clicks or key presses. TestCafe Studio records them too. These actions can increase the test duration and affect the test result. You can delete them from the test during recording.

After the test is recorded, run it to ensure it passes.

Can I use third-party modules in tests?

You can use third-party modules in both codeless tests and test scripts. Use the import statement.

import fs from 'fs';

fixture `fixture`

test('test', async t => {
    const filePath = 'filepath.js';

    await t.expect(fs.existsSync(filePath)).ok();

Use fixture.clientScripts or test.clientScripts in test scripts to inject a module into the tested page. You can use this module inside client functions and selectors.

    // Inject jquery.js as a client script
    ('test', async t => {
        const clientFunction = ClientFunction(() => {
            // You can use $ here
            return $('div').text();

        const text = await clientFunction();

You can use third-party modules in codeless tests: include necessary require declarations in a Run TestCafe Script action.

t.eval in a custom script

How to clear browser cookies and local storages between test runs?

There is no need to do this. TestCafe Studio clears browsing data before starting a test: cookies, local storages, and user profiles.

How do I create user roles?

Codeless tests do not support user roles. However, you can convert your test to a test script and follow this guide.

How do I intercept HTTP requests?

Codeless tests cannot intercept HTTP request. However, you can convert your test to a test script and follow this guide.


I installed TestCafe Studio, but it doesn't start.

On Linux, run TestCafe Studio from the command line. Open the directory where you copied the executable and run the following command:


You should use the command line because certain Linux file managers, including GNOME’s Nautilus, do not launch raw binaries.

Some Linux versions, including CentOS and Arch Linux, may also throw the following error:

The SUID sandbox helper binary was found, but is not configured correctly. Rather than run without sandboxing I’m aborting now. You need to make sure that <testcafe-studio-dir>/chrome-sandbox is owned by root and has mode 4755.

To resolve this issue, go to the directory that contains TestCafe Studio executables (in the Terminal) and change the chrome-sandbox binary’s ownership and access permissions:

sudo chown root chrome-sandbox
sudo chmod 4755 chrome-sandbox

Use debug mode. Start TestCafe Studio from the command line with the debug flag:


"C:\Users\<username>\AppData\Local\Programs\TestCafe Studio\TestCafe Studio.exe" --debug


cd /Applications/"TestCafe"
Contents/MacOS/"TestCafe Studio" --debug

Check if the console contains error messages. If so, take a screenshot and submit it to the Support Center.

Check PATH. On Windows, check if the %PATH% environment variable contains paths to system32 and powershell.

Check your antivirus. Antivirus software may block TestCafe Studio’s initial start. Launch TestCafe Studio once again. This action usually resolves the issue.

I cannot complete registration.

To work around issues that occur during online registration, register TestCafe Studio offline, and file a ticket that describes the issue in the Support Center.

The browser does not launch or TestCafe Studio cannot connect to the browser.

Check your firewall. First, make sure that your firewall does not block ports that TestCafe Studio uses. TestCafe Studio chooses free ports automatically. You can specify custom ports in the Preferences/Settings Dialog and then allow connection to these ports in the firewall settings.

Check your proxy server. Another reason for this problem can be the proxy server you use to access the Internet. If your network is connected to the Web through a proxy, specify the proxy URL in the Preferences/Settings Dialog.

If the issue persists, submit a ticket to the Support Center.

The browser opens an empty page whose URL ends with 'about:error' when I start recording.

Open the URL. Click Open Tested Page in the Test Editor toolbar or the page URL in the Fixture Editor. The website may be unavailable or the URL may be incorrect.

Use the recording browser. Try opening the tested page in the browser you use for recording if this browser is not your default.

Check the network configuration. Ensure that the hostname, port and proxy server settings are correct as described in the previous question.

Try a different test. Run a different test against the same page in TestCafe Studio and open-source TestCafe. Check if it runs without errors.

If the issue persists, submit a ticket to the Support Center.

I cannot record or run tests on macOS.

Open System Preferences > Security & Privacy > Privacy.

TestCafe Studio requires the following permissions:

  • Automation permission for all installed browsers, Automation Permission
  • Screen Recording permission (requires application restart). Recording Permission

If these permissions are already enabled, uncheck the check boxes, then check them again, and restart TestCafe Studio. If this does not fix the issue, execute the following command to reset permissions:

tccutil reset All com.devexpress.testcafestudio

MacOS will display dialog boxes with permission requests again when you run TestCafe Studio.

If the issue persists, submit a ticket to the Support Center.

When I start recording, test steps are not replayed as they are during test run.

After you start recording new steps in a test, TestCafe Studio replays the existing test actions. The playback is performed according to Record Configuration settings. Check these settings and adjust them so they match the Run Configuration.

TestCafe Studio does not fail when JavaScript errors occur on the page during recording. During test runs, this is controlled by the Fail if a JavaScript error occurs setting in the Run Configuration.

When I run a test, I get an unexpected error.

The most common reason for this is a JavaScript error on the tested page. Load this page in the browser, open the console and see if the page has any errors. In case there are errors, you can either fix them or disable the Fail if a JavaScript error occurs setting in the Run Configuration to skip them.

A test fails because TestCafe Studio could not find the required page element.

This happens when a test action Selector does not match any DOM element, the element is not visible, or another element overlaps the target element.

To determine the cause of this issue, do the following:

Codeless Tests

  1. Open the test run report, expand the failed test and click Go to the failed action. Codeless test report
  2. Click Record button Record test actions to play back this test with Visual Test Recorder. When TestCafe Studio tries to execute a step that fails, it throws an error.
  3. You can focus the selector input to highlight elements that match this selector in the browser. (Note, however, that TestCafe Studio does not scroll the page.) Perform this operation after each of the following steps to ensure that the selector is working correctly.
  4. You can use the Element Picker to re-generate the element’s selector (the current selector is rewritten). Click Pick a target element, select the target element in the browser, and run the test again.
  5. If the selector matches several elements, test actions and assertions are performed with the first element in the matched set. Append nth(0) to the selector and check whether the target element is highlighted. If it is not, add selector methods to pick the right element.
  6. Check that the target element is visible and the browser window is scrolled to this element’s position. If the page isn’t scrolled to the target element (but you can scroll it to the element manually), it may indicate that the page uses virtual scrolling. In this instance, add the Hover action to emulate hover over an element or area where virtual scrolling is triggered.
  7. Use the browser’s Developer Tools to check if the target element is inside an <iframe>. If it is, add the Switch to Iframe action before the failed step to switch the browsing context (use the Element Picker to select the <iframe>). Ensure that the selector in the Switch to Iframe action identifies the correct <iframe>.
  8. The target element may not be visible due to layout adaptivity. Try resizing the browser window and focus the selector input each time the layout changes. If the target element only displays at a specific width, use the Maximize Window and Resize Window actions to set a sufficient window size.
  9. In rare cases (complex animations or event handling), increased test speed during test run can cause failures. Specify a smaller value for the Speed option in the record or run configuration to slow down the test.

Test Scripts

  1. Open the test run report and expand the failed test. The error message in the test run report indicates which selector has failed. Test script report
  2. Add the t.debug method before this selector to stop test execution before it reaches this point.
  3. Run the test and wait until the browser stops at the breakpoint.
  4. After this, use the browser’s Developer Tools to check that:
    • the element is present on the page;
    • the element and its parents are visible (TestCafe considers it visible if it does not have display set to none, visibility set to hidden or the zero width or height);
    • the element’s part targeted by the action is visible (the center of the element, or a point specified by the offsetX and offsetY parameters);
    • the element is not in an <iframe> (if it is, use the t.switchToIframe method to switch to the appropriate <iframe>).
  5. Run the test in full screen mode. Use the t.maximizeWindow and t.resizeWindow actions to control the browser window size. If the test passes, it indicates that your webpage hides the target element when the window size is decreased.
  6. Decrease the Speed value in the run configuration to slow down the test.

You can also update TestCafe Studio to the latest version to see if the problem persists.

TestCafe reports that a request has failed.

When TestCafe does not receive a successful response from a server, it outputs the following error:

A request to has failed.
Use quarantine mode to perform additional attempts to execute this test.

You can use quarantine mode to complete tests if this problem occurs infrequently.

However, we recommend that you determine the cause of this issue and address it.

This error can occur in the following situations:

The Web server is not responding

Check if the Web and DNS servers are online and configured to accept requests to this URL.

Unstable or improperly configured network connection

  • Check the network connection settings.
  • Ensure that your network equipment works properly. If possible, establish a direct connection to the Internet/Web server.
  • Check the proxy server’s settings or try a different proxy server.
  • Use a VPN.
  • Connect to a different network.
When I edit a test while recording in Safari, TestCafe Studio lags and the browser reflects changes with a delay.

This can happen when the browser window is inactive or collapsed because macOS throttles browser windows in the background.

To fix this issue, keep the browser window at least partially visible during recording. If this is not possible, follow these steps to disable throttling:

  1. Ensure the Terminal has full access to the file system. Open System Preferences > Security & Privacy > Privacy > Full Disk Access and put a tick next to Terminal.
  2. Enable the Debug menu in Safari with the following command:

    defaults write IncludeInternalDebugMenu 1
  3. Restart Safari.

  4. Open the Debug menu and click Miscellaneous Flags > Disable Hidden Page Timer Throttling.
I am stuck debugging failed tests. Can I obtain more information that would help me identify issues?

TestCafe Studio has the following features that facilitate identifying error causes:

Many TestCafe Studio bugs, such as issues with test playback, stem from underlying product malfunction. To diagnose issues with the TestCafe Framework and the TestCafe Hammerhead reverse proxy, launch TestCafe Studio with the --trace-logs flag. TestCafe Studio will generate a debug log and place it in the testcafe_output.log file in the root folder of your test project.

If you are unable to diagnose the issue with these techniques, you can run tests in the open-source TestCafe to record a video of the test run or take full-page screenshots.

Install TestCafe from npm and run tests from the command line. Do the following in testcafe command arguments:

You can also specify screenshot path patterns to use values like date, time, or browser name in subdirectory names.