How To Pass Experimental Chrome Options In Puppeteer

I have an application written in python/selenium which set some experimental options on the chrome driver: from selenium import webdriver from selenium.webdriver.chrome.options imp

Solution 1:

I.) Normally you should be able to set any experimental features among the args if you are able to position them between the --flag-switches-begin and --flag-switches-end flags and you give them in the following format: Pascal case option names, separated by a single comma without a space. E.g. if you want to set enable-nacl and network-service:

--enable-features=EnableNacl,NetworkService

Experimental features can be checked here: chrome://flags if they are indeed enabled.

The Command Line of Chrome/Chromium can be checked here: chrome://version to see if the flags are added at the launch.

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II.) For me this solution haven't worked (it doesn't mean it wouldn't work for you, it worths a try). So I use a workaround of creating a Chrome profile (Experimental Profile 1) where I enable manually the experimantal flags and then using this profile with puppeteer (--user-data-dir= and --profile-directory= are required):

const puppeteer = require('puppeteer')

asyncfunctionfn() {
  const browser = await puppeteer.launch({
    headless: false,
    args: [
      // '--enable-features=EnableNacl,NetworkService','--user-data-dir=C:\\Users\\user.name\\AppData\\Local\\Chromium\\User Data',
      '--profile-directory=Experimental Profile 1'
    ]
  })
  const page = await browser.newPage()

  await page.goto('chrome://flags/#enable-nacl')
}
fn()

The example above is for Windows, see more platforms and more info here.

Note: You can retrieve executable and profile paths on the chrome://version page.

Note 2: The example above can be run only with headless: false as headless mode cannot visit invalid URLs like chrome://flags/#enable-nacl but the user profile should work. If it isn't then there is a known chromium bug related to relative path of data dir which be solved with path.resolve, e.g.:

const path = require('path')
const browser = await puppeteer.launch({ headless: true, args: [`--user-data-dir=${path.resolve(__dirname, 'User Data') }`] })

[source]

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Edit

Actually the options you want to set are only called experimental options by ChromeDriver but available as chrome policies at chrome://policy page. Make sure you've set Show policies with no value set to see them.

But as far as I see it doesn't provide a simple solution (e.g. in case of Windows you are limited to set it via registry). After searching on GitHub I've found in this discussion that chrome_options.add_experimental_option is not implemented in puppeteer as in ChromeDriver. But in puppeteer-extra there is a dedicated plugin for this, called: user-preferences.

For example:

const puppeteer = require('puppeteer-extra')
puppeteer.use(require('puppeteer-extra-plugin-user-preferences')({ userPrefs: {
  download: {
    prompt_for_download: false
  }
}}))
const browser = await puppeteer.launch()

Reference of pref names and their access: https://chromium.googlesource.com/chromium/src/+/master/chrome/common/pref_names.cc