What is Microsoft Silverlight? What to know about the browser plugin and why it's being shut down (2024)

• Microsoft Silverlight is a component of many web browsers that lets them play music and videos.
• Silverlight used to be incredibly popular, but was eventually made obsolete by HTML5.
• Almost no major web browser still uses Silverlight, and it will be fully shut down in October 2021.
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Microsoft Silverlight is a component in many web browsers that helps them stream and display video, music, clickable menus, and other types of “rich media” content. Launched in 2007, it was intended as a replacement forAdobe Flash, which was the de facto plugin for playing media online at the time.

Silverlight has a troubled history, though, and has been largely abandoned by Microsoft, third-party developers, and users since about 2015. If you’ve heard of Silverlight, it’s probably from Netflix nagging you to install it a few years ago.

Microsoft will completely retire the remaining Silverlight elements in October 2021. But before then, here’s what you should know about Silverlight

What is Microsoft Silverlight?

As stated, Silverlight is a browser plugin that was meant to help users stream videos and use websites more easily. Its software development kit (SDK) and other resources are still available to download for free.

Silverlight started strong – NBC even used the platform to stream the 2008 Summer Olympics in Beijing – and the plugin was available for most major browsers for several years. Silverlight directly supported most video and animation formats like H.264, MP3, MP4, and WMV files without forcing the user to download additional software.

Silverlight ran in the background in most browsers, although notably many Mac users in the early-to-mid 2010s faced issues running Netflix because of it.

The platform soon became redundant, however, with the release of HTML5.HTML5 is a rich media platform integrated into all modern web browsers that eliminates the need to install a plug-in like Silverlight (or Adobe Flash, for that matter).

Major online partners quickly moved from Silverlight to HTML5 - Netflix and Amazon Prime Video both made the transition in 2015, for example. Google Chrome dropped support for Silverlight in 2015 and Firefox abandoned the platform in 2017. Macs haven't supported Silverlight since 2016. Even most versions of Microsoft's Internet Explorer stopped using Silverlight at the start of 2020.

Currently, the only major browser that continues to support Silverlight is Internet Explorer 11 for Windows 10. And even it will discontinue it by the end of 2021.

The end of Silverlight

Microsoft hasn't actively developed Silverlight since about 2015, and the platform will be completely retired on October 12, 2021. At that time, Microsoft will stop providing updates for the platform, and will remove access to the installer as well as the SDK and other resources.

However, since Silverlight has a "perpetual license," existing Silverlight applications won't be shut down. It just means that they won't be updated, and it may be harder to find a browser that can run them.

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