playwright

What is playwright?

Playwright is a Node.js library developed by Microsoft that allows developers to automate browser actions for testing and scraping purposes. It supports multiple browsers, including Chromium, Firefox, and WebKit, and provides a high-level API to control headless or full browsers over the DevTools Protocol.

What are playwright's main functionalities?

Browser Automation

Automate browser actions such as opening a page, clicking elements, and navigating through websites.

const { chromium } = require('playwright');

(async () => {
  const browser = await chromium.launch();
  const page = await browser.newPage();
  await page.goto('https://example.com');
  // other actions...
  await browser.close();
})();

Web Scraping

Extract data from web pages by selecting elements and retrieving their content.

const { firefox } = require('playwright');

(async () => {
  const browser = await firefox.launch();
  const page = await browser.newPage();
  await page.goto('https://example.com');
  const data = await page.textContent('.some-element');
  console.log(data);
  await browser.close();
})();

Automated Testing

Write automated tests for web applications, including assertions to validate the behavior of the application.

const { webkit } = require('playwright');
const { expect } = require('@playwright/test');

(async () => {
  const browser = await webkit.launch();
  const page = await browser.newPage();
  await page.goto('https://example.com');
  const title = await page.title();
  expect(title).toBe('Example Domain');
  await browser.close();
})();

Cross-Browser Testing

Test web applications across multiple browsers to ensure compatibility and consistent behavior.

const { chromium, firefox, webkit } = require('playwright');

(async () => {
  for (const browserType of [chromium, firefox, webkit]) {
    const browser = await browserType.launch();
    const page = await browser.newPage();
    await page.goto('https://example.com');
    // Perform tests across different browsers
    await browser.close();
  }
})();

Mobile Emulation

Emulate mobile devices to test responsive designs and touch interactions.

const { chromium, devices } = require('playwright');
const iPhone11 = devices['iPhone 11 Pro'];

(async () => {
  const browser = await chromium.launch();
  const context = await browser.newContext({
    ...iPhone11
  });
  const page = await context.newPage();
  await page.goto('https://example.com');
  // Emulate mobile device actions and layout
  await browser.close();
})();

Other packages similar to playwright

selenium-webdriver

Selenium WebDriver is one of the most well-known browser automation tools. It requires separate drivers for each browser and is generally slower than Playwright due to its reliance on the WebDriver protocol, which is more standardized but less performant.

puppeteer

Puppeteer is another Node.js library that provides a high-level API to control Chrome or Chromium over the DevTools Protocol. It is similar to Playwright but was developed by the Chrome DevTools team and initially focused on Chrome, whereas Playwright supports multiple browsers out of the box.

cypress

Cypress is a front-end testing tool built for the modern web. It is both a library for writing tests and a test runner that executes the tests. Cypress is known for its rich interactive test runner interface but does not support as many browsers as Playwright and is primarily focused on testing rather than general browser automation.

nightwatch

Nightwatch.js is an automated testing framework for web applications and websites, written in Node.js and using the W3C WebDriver API. It is designed to simplify the process of writing end-to-end tests. Nightwatch is less feature-rich compared to Playwright and is more focused on the testing aspect.

README

Playwright

API | FAQ | Contributing

Playwright is a Node library to automate the Chromium, WebKit and Firefox browsers. Playwright is focused on enabling cross-browser web automation platform that is ever-green, capable, reliable and fast. Our primary goal with Playwright is to improve automated UI testing by eliminating flakiness, improving the speed of execution and offering insights into the browser operation. Playwright runs headless versions of these browsers by default, but can be configured to run the full versions.

Installation

npm i playwright

This installs Playwright along with its dependencies and the browser binaries. Browser binaries are about 50-100MB each, so expect the installation network traffic to be substantial.

Usage

Playwright can be used to create a browser instance, open pages, and then manipulate them. See API docs for a comprehensive list.

Examples

Page screenshot

This code snippet navigates to example.com in WebKit, and saves a screenshot.

const pw = require('playwright');

(async () => {
  const browser = await pw.webkit.launch(); // or 'chromium', 'firefox'
  const context = await browser.newContext();
  const page = await context.newPage();

  await page.goto('https://www.example.com/');
  await page.screenshot({ path: 'example.png' });

  await browser.close();
})();

Evaluate script

This code snippet navigates to example.com in Firefox, and executes a script in the page context.

const pw = require('playwright');

(async () => {
  const browser = await pw.firefox.launch(); // or 'chromium', 'webkit'
  const context = await browser.newContext();
  const page = await context.newPage();

  await page.goto('https://www.example.com/');
  const dimensions = await page.evaluate(() => {
    return {
      width: document.documentElement.clientWidth,
      height: document.documentElement.clientHeight,
      deviceScaleFactor: window.devicePixelRatio
    }
  })
  console.log(dimensions);

  await browser.close();
})();

Limitations

WebKit support on Windows is based on the WSL / Docker containers. We are working on the WinCairo-based version of the browser, but it'll be available later. Stay tuned!

Contributing

Check out our contributing guide.

FAQ

Q: How does Playwright relate to Puppeteer?

We are the same team that built Puppeteer. Puppeteer proved that there is a lot of interest in the new generation of ever-green, capable and reliable automation drivers. With Playwright, we'd like to take it one step further and offer the same functionality for all the popular rendering engines. We'd like to see Playwright vendor-neutral and shared goverened.

With Playwright, we are making the APIs more testing friendly as well. We are taking the lessons learned from Puppeteer and incorporate them into the API, for example, user agent / device emulation is set up consistently on the BrowserContext level to enable multi-page scenarios, click now waits for the element to be available and visible by default, etc.

Playwright also aims at being even more cloud-friendly. Rather than a single page, BrowserContext abstraction is now central to the library operation. BrowserContexts are isolated, they can be either created locally or provided by the server-side factories.

All the changes and improvements above would require breaking changes to the Puppeteer API, so we chose to start with a clean slate instead. Due to the similarity of the concepts and the APIs, migration between the two is still a mechanical task.

Q: What about the WebDriver?

WIP

• [capabilities] With Playwright, we aim at providing a more capable driver, including support for mobile viewports, touch, web & service workers, geolocation, csp, cookie policies, permissions, accessibility, etc.

• [reliability] Playwright's communication with all the browsers is event-driven, based on the full-duplex transport, which eliminates the need for polling. (Polling is one of the greatest sources of test flakiness).

Q: Is Playwright ready?

Playwright is ready for your feedback. It respects semver, so please expect some API breakages as we release 1.0. All we can promise is that those breakages are going to be based on your feedback with the sole purpose of making our APIs better.

Playwright is being actively developed as we get to the feature parity across Chromium, Firefox and WebKit. Progress on each browser can be tracked on the Is Playwright Ready? page, which shows currently failing tests per browser.

Resources

• API documentation