Chromedriver

Appium supports automating Android web pages (in Chrome and the built-in Browser) and hybrid apps that are Chrome-backed, by managing a Chromedriver instance and proxying commands to it when necessary. It comes bundled with the latest version of Chromedriver, installed through the npm package appium-chromedriver (Github: appium-chromedriver).

Unfortunately, with each update to Chromedriver there is an increase in the minimum supported version of Chrome, such that older devices are often unable to be automated with the bundled version. In the Appium server logs there will be an error like:

An unknown server-side error occurred while processing the command.

Original error: unknown error: Chrome version must be >= 55.0.2883.0

To get around this, Appium can be configured to use a particular Chromedriver version, either at install time, by either passing the –chromedriver_version config property, e.g.,

npm install appium –chromedriver_version=”2.16″

Or specifying the version in the CHROMEDRIVER_VERSION environment variable, e.g,

CHROMEDRIVER_VERSION=2.20 npm install appium

This can also be set to LATEST to get the most recent version.

Finally, a version can be specified at runtime, by specifying the –chromedriver-executable server flag, along with the full path to the Chromedriver executable which was manually downloaded, e.g.,

appium –chromedriver-executable /path/to/my/chromedriver

Chromedriver/Chrome compatibility

The following is a list of Chromedriver versions and their corresponding minimum Chrome version that is automatable:

Version	Minimum Chrome Version	Link to Chromedriver
2.44	69.0.3497.0	v2.44
2.43	69.0.3497.0	v2.43
2.42	68.0.3440.0	v2.42
2.41	67.0.3360.0	v2.41
2.40	66.0.3359.0	v2.40
2.39	66.0.3359.0	v2.39
2.38	65.0.3325.0	v2.38
2.37	64.0.3282.0	v2.37
2.36	63.0.3239.0	v2.36
2.35	62.0.3202.0	v2.35
2.34	61.0.3163.0	v2.34
2.33	60.0.3112.0	v2.33
2.32	59.0.3071.0	v2.32

The complete list of available Chromedriver releases is here. To find the minimum supported version for any particular version, get the Chromium source code, check out the release commit, and check the variable kMinimumSupportedChromeVersion in the file src/chrome/test/chromedriver/chrome/version.cc. (To find the release commits, you can use git log –pretty=format:’%h | %s%d’ | grep -i “Release Chromedriver version”.)

Automatic discovery of compatible Chromedriver

Beginning with Appium 1.8.0, Appium is able to pick the correct Chromedriver for the version of Chrome under test. While Appium only comes bundled with the Chromedriver most recently released at the time of the Appium version’s release, more Chromedriver versions can be downloaded and either placed inside the Appium installation (not recommended since upgrading Appium will remove them) or in a custom location, which can be indicated to Appium with the chromedriverExecutableDir desired capability. This capability is the absolute path to the directory in which you have placed one or more Chromedriver executables.

As well, since new versions of Chromedriver may be available that were not when an Appium version was released, a custom mapping of Chromedrivers to the minimum Chrome version they support can be given to Appium through the chromedriverChromeMappingFile desired capability. This should be the absolute path to a file with the mapping in it. The contents of the file need to be parsable as a JSON object, like:

{

“2.42”: “63.0.3239”,

“2.41”: “62.0.3202”

}

Installing an network issues

When Appium is installed it needs to download Chromedriver, so there is the possibility that there could be network problems that make the install fail.

By default Chromedriver is retrieved from https://chromedriver.storage.googleapis.com/. To use a mirror of the ChromeDriver binaries use npm config property chromedriver_cdnurl.

npm install appium-chromedriver –chromedriver_cdnurl=http://npm.taobao.org/mirrors/chromedriver

Or add the property into your .npmrc file.

chromedriver_cdnurl=http://npm.taobao.org/mirrors/chromedriver

Another option is to use PATH variable CHROMEDRIVER_CDNURL.

CHROMEDRIVER_CDNURL=http://npm.taobao.org/mirrors/chromedriver npm install appium-chromedriver

It may also be necessary to adjust network proxy and firewall settings to allow the download to occur.