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Version: 1.15

Debugging tools

Playwright scripts work with existing debugging tools, like Node.js debuggers and browser developer tools. Playwright also introduces new debugging features for browser automation.

Playwright Inspector#

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

Playwright Inspector

Playwright Trace Viewer#

Playwright Trace Viewer is a GUI tool that helps troubleshooting test runs in a post-mortem manner.

Playwright Trace Viewer

Run in 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 slowMo option to slow down execution and follow along while debugging.

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

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
Chromium Developer Tools

Using a 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 });

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

Run in Debug Mode#

Set the PWDEBUG environment variable to run your scripts in debug mode. Using PWDEBUG=1 will open Playwright Inspector.

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.
# Linux/macOSPWDEBUG=console npm run test
# Windows with cmd.exeset PWDEBUG=consolenpm run test
# Windows with PowerShell$env:PWDEBUG="console"npm run test

Selectors in Developer Tools Console#

When running in Debug Mode with PWDEBUG=console, a playwright object is available in Developer tools console.

  1. Run with PWDEBUG=console
  2. Setup a breakpoint to pause the execution
  3. Open the console panel in browser developer tools
  4. Use the playwright API
    • playwright.$(selector): Highlight the first occurrence of the selector. This reflects how page.$ would see the page.
    • playwright.$$(selector): Highlight all occurrences of the selector. This reflects how page.$$ would see the page.
    • playwright.inspect(selector): Inspect the selector in the Elements panel.
    • playwright.clear(): Clear existing highlights.
    • playwright.selector(element): Generate a selector that points to the element.
Highlight selectors

Visual Studio Code debugger (Node.js)#

The VS Code debugger can be used to pause and resume execution of Playwright scripts with breakpoints. The debugger can be configured in two ways.

Use launch config#

Setup launch.json configuration for your Node.js project. Once configured launch the scripts with F5 and use breakpoints.

Use the JavaScript Debug Terminal#

  1. Open JavaScript Debug Terminal
  2. Set a breakpoint in VS Code
    • Use the debugger keyword or set a breakpoint in the VS Code UI
  3. Run your Node.js script from the terminal

Verbose API logs#

Playwright supports verbose logging with the DEBUG environment variable.

# Linux/macOSDEBUG=pw:api npm run test
# Windows with cmd.exeset DEBUG=pw:apinpm run test
# Windows with PowerShell$env:DEBUG="pw:api"npm run test