Playwright scripts work with existing debugging tools, like Node.js debuggers and browser developer tools. Playwright also introduces new debugging features for browser automation.
- Run in headful mode
- Visual Studio Code debugger (Node.JS)
- Browser Developer Tools
- Run in Debug Mode
- Verbose API logs
#Run in headful 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
slow_mo option to slow down execution and follow along while debugging.
#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
launch.json configuration for your Node.js project. Once configured launch the scripts with F5 and use breakpoints.
launch.json configuration. To use it:
- Set a breakpoint in VS Code
- Use the
debuggerkeyword or set a breakpoint in the VS Code UI
- Use the
- Run your Node.js script from the terminal
#Browser Developer Tools
You can use browser developer tools in Chromium, Firefox and WebKit while running a Playwright script. 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
For WebKit: Note that launching WebKit Inspector during the execution will prevent the Playwright script from executing any further.
#API for Chromium
In Chromium, you can also open developer tools through a launch option.
#Run in Debug Mode
PWDEBUG environment variable to run your scripts in debug mode. This configures the browser for debugging.
With PWDEBUG, the following defaults are configured for you:
- Run in headful: With PWDEBUG, browsers always launch in headful mode
- Disables timeout: PWDEBUG sets timeout to 0 (= no timeout)
- Preserve DevTools preferences: When used with
devtools: true, PWDEBUG preserves the docked/undocked state of Chrome DevTools
PWDEBUG configures a
playwright object in the browser to highlight Playwright selectors. This can be used to verify text or composite selectors. To use this:
- Setup a breakpoint to pause the execution
- Open the console panel in browser developer tools
- Use the
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.
#Evaluate Source Maps
PWDEBUG also enables source maps for
#Verbose API logs
Playwright supports verbose logging with the
DEBUG environment variable.