Use the Silverlight plugin to play audio and video

This article is no longer maintained, so its content might be out of date.

Support ended for all NPAPI plugins, except for Adobe Flash, in Firefox version 52. See this article for details.

Microsoft Silverlight is a plugin used by some websites to display multimedia content. This article describes how to check whether you have Silverlight installed and how to install or update it.

Silverlight is not available for the Linux platform and the only open source implementation of Silverlight, called Moonlight, is not developed anymore. It can be still compiled from source but it is not recommended to use it. More information can be found at the Moonlight installation page.

Checking for Silverlight

To determine whether you have the Silverlight plugin installed, visit Microsoft's Get Microsoft Silverlight page.

If Silverlight is installed, you will see a message with your Silverlight version.


Installing Silverlight

If you do not have Silverlight installed, follow the Installation Instructions on Microsoft's Get Microsoft Silverlight page.

Updating Silverlight

If Silverlight is installed but your version is outdated, the Get Microsoft Silverlight page will show your installed version and the current version of Silverlight.


Click the current version link to manually download and install the latest version of Silverlight.

Note: Silverlight has an automatic update feature so manual updates may not be necessary. See the Microsoft Silverlight Configuration Dialog Box article and the Microsoft Silverlight Updater article for details.

Uninstalling Silverlight

To uninstall Silverlight, follow the Uninstall Silverlight instructions on Microsoft's Get Microsoft Silverlight page.

Silverlight is installed but does not work

Mozilla blocks older versions of Silverlight, causing sites like Netflix to display a message asking you to install Silverlight. To fix this, please update your installation of Silverlight to the latest version by visiting Microsoft's Get Microsoft Silverlight page.

In some cases, this may not resolve the problem and you will need to manually activate the Silverlight plugin:

  1. Click the menu button Fx89menuButton, click Add-ons and themes and select Plugins.
  2. Find Silverlight in the list of plugins and select Always Activate in its drop-down menu.

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