Using Plugins


Widevine is a digital content decryption module from Google. By default, EO.WebBrowser will automatically download and update Widevine from Google when it starts. So no additional steps is needed to support Widevine. However:

  • Downloading/updating Widevine can take a few minutes. If you wish the plugin to be loaded immediately upon start, you can use EngineOptions.PreinstalledPluginsDir to specify the location of a preinstalled copy of the Widevine plugin. See steps below for details;
  • Typically Widevine protected contents also uses advanced codecs such as mp4. As such in order to play Widevine protected contents, you would also need to call EngineOptions.AllowProprietaryMediaFormats to allow advanced proprietary media formats.

Follow these steps to load Widevine from EO.WebEngine.EngineOptions.PreinstalledPluginsDir:

  1. Set EO.WebEngine.EngineOptions.PreinstalledPluginsDir in your code to the folder you wish to place Widevine binaries. For example:

    EO.WebEngine.EngineOptions.Default.PreinstalledPluginsDir = @"c:\Plugins";
  2. Run TabbedBrowser sample application (or your application that uses EO.WebBrowser) and load any web page. This will trigger the browser engine to automatically download Widevine from Google. By default, the downloaded binary will be inside

    %LOCALAPPDATA%\EO.WebEngine\User Data\WidevineCdm\version


    • %LOCALAPPDATA% is the value of your current user's local application data directory. For example, "c:\Users\John\AppData\Local";
    • version is the actual version of the Widevine binary. For example, "4.10.2391.0";

    As such an example of the full path could be:

    c:\Users\John\AppData\Local\EO.WebEngine\User Data\WidevineCdm\4.10.2391.0
  3. Create subfolder WidevineCdm inside EO.WebEngine.EngineOptions.PreinstalledPluginsDir;
  4. Copy all files from inside the version folder from step 2 into WidevineCdm folder in step 3. Note that while all the files reside inside WidevineCdm\version in step 2, they reside directly inside WidevineCdm without version sub-folder here;

Now you can run your application and Widevine will be loaded from the directory you specified.


EO.WebBrowser includes a built-in PDF plugin and it is enabled by default. You can disable it by setting EngineOptions.DisableBuiltInPlugIns to true. For example:

EO.WebEngine.EngineOptions.Default.DisableBuiltInPlugIns = true;

Note that this will also disable Widevine plugin.

Adobe Flash

Since Adobe no longer supports Flash Player after December 31, 2020 and blocked Flash content from running in Flash Player beginning January 12, 2021, Adobe Flash is no longer supported.