15. Playwright API - class: BrowserType - 《Playwright v1.12 Document》

class: BrowserType

class: BrowserType

BrowserType provides methods to launch a specific browser instance or connect to an existing one. The following is a typical example of using Playwright to drive automation:

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

browserType.connect(options)
browserType.executablePath()
browserType.launch([options])
browserType.launchPersistentContext(userDataDir, [options])
browserType.launchServer([options])
browserType.name()

browserType.connect(options)

options <Object>
- wsEndpoint <string> A browser websocket endpoint to connect to. required
- slowMo <number> Slows down Playwright operations by the specified amount of milliseconds. Useful so that you can see what is going on. Defaults to 0.
- logger <Logger> Logger sink for Playwright logging.
- timeout <number> Maximum time in milliseconds to wait for the connection to be established. Defaults to 30000 (30 seconds). Pass 0 to disable timeout.
returns: <Promise<Browser>>

This methods attaches Playwright to an existing browser instance.

browserType.executablePath()

returns: <string> A path where Playwright expects to find a bundled browser executable.

browserType.launch([options])

options <Object> Set of configurable options to set on the browser. Can have the following fields:
- headless <boolean> Whether to run browser in headless mode. More details for Chromium and Firefox. Defaults to true unless the devtools option is true.
- executablePath <string> Path to a browser executable to run instead of the bundled one. If executablePath is a relative path, then it is resolved relative to current working directory. Note that Playwright only works with the bundled Chromium, Firefox or WebKit, use at your own risk.
- args <Array<string>> Additional arguments to pass to the browser instance. The list of Chromium flags can be found here.
- ignoreDefaultArgs <boolean|Array<string>> If true, Playwright does not pass its own configurations args and only uses the ones from args. If an array is given, then filters out the given default arguments. Dangerous option; use with care. Defaults to false.
- proxy <Object> Network proxy settings.
  - server <string> Proxy to be used for all requests. HTTP and SOCKS proxies are supported, for example http://myproxy.com:3128 or socks5://myproxy.com:3128. Short form myproxy.com:3128 is considered an HTTP proxy.
  - bypass <string> Optional coma-separated domains to bypass proxy, for example ".com, chromium.org, .domain.com".
  - username <string> Optional username to use if HTTP proxy requires authentication.
  - password <string> Optional password to use if HTTP proxy requires authentication.
- downloadsPath <string> If specified, accepted downloads are downloaded into this folder. Otherwise, temporary folder is created and is deleted when browser is closed.
- firefoxUserPrefs <Object> Firefox user preferences. Learn more about the Firefox user preferences at about:config.
- handleSIGINT <boolean> Close the browser process on Ctrl-C. Defaults to true.
- handleSIGTERM <boolean> Close the browser process on SIGTERM. Defaults to true.
- handleSIGHUP <boolean> Close the browser process on SIGHUP. Defaults to true.
- logger <Logger> Logger sink for Playwright logging.
- timeout <number> Maximum time in milliseconds to wait for the browser instance to start. Defaults to 30000 (30 seconds). Pass 0 to disable timeout.
- env <Object<string, string|number|boolean>> Specify environment variables that will be visible to the browser. Defaults to process.env.
- devtools <boolean> Chromium-only Whether to auto-open a Developer Tools panel for each tab. If this option is true, the headless option will be set false.
- slowMo <number> Slows down Playwright operations by the specified amount of milliseconds. Useful so that you can see what is going on.
returns: <Promise<Browser>> Promise which resolves to browser instance.

You can use ignoreDefaultArgs to filter out --mute-audio from default arguments:

const browser = await chromium.launch({  // Or 'firefox' or 'webkit'.
  ignoreDefaultArgs: ['--mute-audio']
});

Chromium-only Playwright can also be used to control the Chrome browser, but it works best with the version of Chromium it is bundled with. There is no guarantee it will work with any other version. Use executablePath option with extreme caution.

If Google Chrome (rather than Chromium) is preferred, a Chrome Canary or Dev Channel build is suggested.

In browserType.launch([options]) above, any mention of Chromium also applies to Chrome.

See this article for a description of the differences between Chromium and Chrome. This article describes some differences for Linux users.

browserType.launchPersistentContext(userDataDir, [options])

userDataDir <string> Path to a User Data Directory, which stores browser session data like cookies and local storage. More details for Chromium and Firefox.
options <Object> Set of configurable options to set on the browser. Can have the following fields:
- headless <boolean> Whether to run browser in headless mode. More details for Chromium and Firefox. Defaults to true unless the devtools option is true.
- executablePath <string> Path to a browser executable to run instead of the bundled one. If executablePath is a relative path, then it is resolved relative to current working directory. BEWARE: Playwright is only guaranteed to work with the bundled Chromium, Firefox or WebKit, use at your own risk.
- args <Array<string>> Additional arguments to pass to the browser instance. The list of Chromium flags can be found here.
- ignoreDefaultArgs <boolean|Array<string>> If true, then do not use any of the default arguments. If an array is given, then filter out the given default arguments. Dangerous option; use with care. Defaults to false.
- proxy <Object> Network proxy settings.
  - server <string> Proxy to be used for all requests. HTTP and SOCKS proxies are supported, for example http://myproxy.com:3128 or socks5://myproxy.com:3128. Short form myproxy.com:3128 is considered an HTTP proxy.
  - bypass <string> Optional coma-separated domains to bypass proxy, for example ".com, chromium.org, .domain.com".
  - username <string> Optional username to use if HTTP proxy requires authentication.
  - password <string> Optional password to use if HTTP proxy requires authentication.
- acceptDownloads <boolean> Whether to automatically download all the attachments. Defaults to false where all the downloads are canceled.
- downloadsPath <string> If specified, accepted downloads are downloaded into this folder. Otherwise, temporary folder is created and is deleted when browser is closed.
- handleSIGINT <boolean> Close the browser process on Ctrl-C. Defaults to true.
- handleSIGTERM <boolean> Close the browser process on SIGTERM. Defaults to true.
- handleSIGHUP <boolean> Close the browser process on SIGHUP. Defaults to true.
- logger <Logger> Logger sink for Playwright logging.
- timeout <number> Maximum time in milliseconds to wait for the browser instance to start. Defaults to 30000 (30 seconds). Pass 0 to disable timeout.
- env <Object<string, string|number|boolean>> Specify environment variables that will be visible to the browser. Defaults to process.env.
- devtools <boolean> Chromium-only Whether to auto-open a Developer Tools panel for each tab. If this option is true, the headless option will be set false.
- slowMo <number> Slows down Playwright operations by the specified amount of milliseconds. Useful so that you can see what is going on. Defaults to 0.
- ignoreHTTPSErrors <boolean> Whether to ignore HTTPS errors during navigation. Defaults to false.
- bypassCSP <boolean> Toggles bypassing page’s Content-Security-Policy.
- viewport <?Object> Sets a consistent viewport for each page. Defaults to an 1280x720 viewport. null disables the default viewport.
  - width <number> page width in pixels.
  - height <number> page height in pixels.
- userAgent <string> Specific user agent to use in this context.
- deviceScaleFactor <number> Specify device scale factor (can be thought of as dpr). Defaults to 1.
- isMobile <boolean> Whether the meta viewport tag is taken into account and touch events are enabled. Defaults to false. Not supported in Firefox.
- hasTouch <boolean> Specifies if viewport supports touch events. Defaults to false.
- javaScriptEnabled <boolean> Whether or not to enable JavaScript in the context. Defaults to true.
- timezoneId <string> Changes the timezone of the context. See ICU’s metaZones.txt for a list of supported timezone IDs.
- geolocation <Object>
  - latitude <number> Latitude between -90 and 90.
  - longitude <number> Longitude between -180 and 180.
  - accuracy <number> Non-negative accuracy value. Defaults to 0.
- locale <string> Specify user locale, for example en-GB, de-DE, etc. Locale will affect navigator.language value, Accept-Language request header value as well as number and date formatting rules.
- permissions <Array<string>> A list of permissions to grant to all pages in this context. See browserContext.grantPermissions for more details.
- extraHTTPHeaders <Object<string, string>> An object containing additional HTTP headers to be sent with every request. All header values must be strings.
- offline <boolean> Whether to emulate network being offline. Defaults to false.
- httpCredentials <Object> Credentials for HTTP authentication.
  - username <string>
  - password <string>
- colorScheme <”dark”|”light”|”no-preference”> Emulates 'prefers-colors-scheme' media feature, supported values are 'light', 'dark', 'no-preference'. See page.emulateMedia(options) for more details. Defaults to ‘light‘.
returns: <Promise<BrowserContext>> Promise that resolves to the persistent browser context instance.

Launches browser that uses persistent storage located at userDataDir and returns the only context. Closing this context will automatically close the browser.

browserType.launchServer([options])

options <Object> Set of configurable options to set on the browser. Can have the following fields:
- headless <boolean> Whether to run browser in headless mode. More details for Chromium and Firefox. Defaults to true unless the devtools option is true.
- port <number> Port to use for the web socket. Defaults to 0 that picks any available port.
- executablePath <string> Path to a browser executable to run instead of the bundled one. If executablePath is a relative path, then it is resolved relative to current working directory. BEWARE: Playwright is only guaranteed to work with the bundled Chromium, Firefox or WebKit, use at your own risk.
- args <Array<string>> Additional arguments to pass to the browser instance. The list of Chromium flags can be found here.
- ignoreDefaultArgs <boolean|Array<string>> If true, then do not use any of the default arguments. If an array is given, then filter out the given default arguments. Dangerous option; use with care. Defaults to false.
- proxy <Object> Network proxy settings.
  - server <string> Proxy to be used for all requests. HTTP and SOCKS proxies are supported, for example http://myproxy.com:3128 or socks5://myproxy.com:3128. Short form myproxy.com:3128 is considered an HTTP proxy.
  - bypass <string> Optional coma-separated domains to bypass proxy, for example ".com, chromium.org, .domain.com".
  - username <string> Optional username to use if HTTP proxy requires authentication.
  - password <string> Optional password to use if HTTP proxy requires authentication.
- downloadsPath <string> If specified, accepted downloads are downloaded into this folder. Otherwise, temporary folder is created and is deleted when browser is closed.
- firefoxUserPrefs <Object> Firefox user preferences. Learn more about the Firefox user preferences at about:config.
- handleSIGINT <boolean> Close the browser process on Ctrl-C. Defaults to true.
- handleSIGTERM <boolean> Close the browser process on SIGTERM. Defaults to true.
- handleSIGHUP <boolean> Close the browser process on SIGHUP. Defaults to true.
- logger <Logger> Logger sink for Playwright logging.
- timeout <number> Maximum time in milliseconds to wait for the browser instance to start. Defaults to 30000 (30 seconds). Pass 0 to disable timeout.
- env <Object<string, string|number|boolean>> Specify environment variables that will be visible to the browser. Defaults to process.env.
- devtools <boolean> Chromium-only Whether to auto-open a Developer Tools panel for each tab. If this option is true, the headless option will be set false.
returns: <Promise<BrowserServer>> Promise which resolves to the browser app instance.

Launches browser server that client can connect to. An example of launching a browser executable and connecting to it later:

const { chromium } = require('playwright');  // Or 'webkit' or 'firefox'.
(async () => {
  const browserServer = await chromium.launchServer();
  const wsEndpoint = browserServer.wsEndpoint();
  // Use web socket endpoint later to establish a connection.
  const browser = await chromium.connect({ wsEndpoint });
  // Close browser instance.
  await browserServer.close();
})();

browserType.name()

returns: <string>

Returns browser name. For example: 'chromium', 'webkit' or 'firefox'.