debug.md

id	title
debug	Debugging Tests

The Playwright inspector is a great tool to help with debugging. It opens up a browser window highlighting the selectors as you step through each line of the test. You can also use the explore button to find other available selectors which you can then copy into your test file and rerun your tests to see if it passes. For debugging selectors, see here.

Playwright Inspector

Playwright Inspector is a GUI tool that helps authoring and debugging Playwright scripts. That's our default recommended tool for scripts troubleshooting.

There are several ways of opening Playwright Inspector:

--debug

• langs: js

• Debugging all Tests

  npx playwright test --debug

• Debugging one test

  npx playwright test example --debug

PWDEBUG

Set the PWDEBUG environment variable to run your scripts in debug mode. This configures Playwright for debugging and opens the inspector.

PWDEBUG=1 npx playwright test

set PWDEBUG=1
npx playwright test

$env:PWDEBUG=1
npx playwright test

# Source directories in the list are separated by : on macos and linux and by ; on win.
PWDEBUG=1 PLAYWRIGHT_JAVA_SRC=<java source dirs> mvn test

# Source directories in the list are separated by : on macos and linux and by ; on win.
set PLAYWRIGHT_JAVA_SRC=<java source dirs>
set PWDEBUG=1
mvn test

# Source directories in the list are separated by : on macos and linux and by ; on win.
$env:PLAYWRIGHT_JAVA_SRC="<java source dirs>"
$env:PWDEBUG=1
mvn test

PWDEBUG=1 pytest -s

set PWDEBUG=1
pytest -s

$env:PWDEBUG=1
pytest -s

PWDEBUG=1 dotnet test

set PWDEBUG=1
dotnet test

$env:PWDEBUG=1
dotnet test

Additional useful defaults are configured when PWDEBUG=1 is set:

• Browsers launch in the headed mode
• Default timeout is set to 0 (= no timeout)

Using PWDEBUG=console will configure the browser for debugging in Developer tools console:

• Runs headed: Browsers always launch in headed mode
• Disables timeout: Sets default timeout to 0 (= no timeout)
• Console helper: Configures a playwright object in the browser to generate and highlight Playwright selectors. This can be used to verify text or composite selectors.

PWDEBUG=console npx playwright test

set PWDEBUG=console
npx playwright test

$env:PWDEBUG="console"
npx playwright test

PWDEBUG=console mvn test

set PWDEBUG=console
mvn test

$env:PWDEBUG="console"
mvn test

PWDEBUG=console pytest -s

set PWDEBUG=console
pytest -s

$env:PWDEBUG="console"
pytest -s

page.pause

Call [method: Page.pause] method from your script when running in headed browser.

// Pause on the following line.
await page.pause();

// Pause on the following line.
page.pause();

# Pause on the following line.
await page.pause()

# Pause on the following line.
page.pause()

// Pause on the following line.
await page.PauseAsync();

Use open or codegen commands in the Playwright CLI:

npx playwright codegen wikipedia.org

mvn exec:java -e -Dexec.mainClass=com.microsoft.playwright.CLI -Dexec.args="codegen wikipedia.org"

playwright codegen wikipedia.org

pwsh bin/Debug/netX/playwright.ps1 codegen wikipedia.org

Stepping through the Playwright script

The Inspector opens up a browser window highlighting the selectors as you step through each line of the test. Use the explore button to find other available selectors which you can then copy into your test file and rerun your tests to see if they pass.

Use the toolbar to play the test or step over each action using the "Step over" action (keyboard shortcut: F10) or resume script without further pauses (F8):

Now we know what action is about to be performed and we can look into the details on that action. For example, when stopped on an input action such as click, the exact point Playwright is about to click is highlighted with the large red dot on the inspected page:

Actionability Logs

By the time Playwright has paused on that click action, it has already performed actionability checks that can be found in the log:

If actionability can't be reached, it'll show action as pending:

Exploring selectors

Use the Explore button to hover over an element on the page and explore it's selector by clicking on it. You can then copy this selector into your tests and rerun your tests to see if they now pass with this selector. You can also debug selectors, checkout our debugging selectors guide for more details.

Browser Developer Tools

You can use browser developer tools in Chromium, Firefox and WebKit while running a Playwright script in headed mode. Developer tools help to:

• Inspect the DOM tree and find element selectors
• See console logs during execution (or learn how to read logs via API)
• Check network activity and other developer tools features

Using a [method: Page.pause] method is an easy way to pause the Playwright script execution and inspect the page in Developer tools. It will also open Playwright Inspector to help with debugging.

For Chromium: you can also open developer tools through a launch option.

await chromium.launch({ devtools: true });

chromium.launch(new BrowserType.LaunchOptions().setDevtools(true));

await chromium.launch(devtools=True)

chromium.launch(devtools=True)

await using var browser = await playwright.Chromium.LaunchAsync(new()
{
  Devtools: true
});

:::note For WebKit: launching WebKit Inspector during the execution will prevent the Playwright script from executing any further. :::

Headed mode

Playwright runs browsers in headless mode by default. To change this behavior, use headless: false as a launch option. You can also use the [option: slowMo] option to slow down execution and follow along while debugging.

await chromium.launch({ headless: false, slowMo: 100 }); // or firefox, webkit

chromium.launch(new BrowserType.LaunchOptions() // or firefox, webkit
  .setHeadless(false)
  .setSlowMo(100));

await chromium.launch(headless=False, slow_mo=100) # or firefox, webkit

chromium.launch(headless=False, slow_mo=100) # or firefox, webkit

// Chromium, Firefox, or Webkit
await using var browser = await playwright.Chromium.LaunchAsync(new()
{
    Headless = false,
    SlowMo = 100
});