Published on November 11, 2019 (over 4 years ago)

Seeing double? Let your users simulcast (aka restream) to any social platform

Steve Heffernan
By Steve Heffernan2 min readProduct

A common request from our Live Streaming API customers is the ability to forward a live stream on to social networks like Youtube, Facebook, Twitch, and Periscope. This process is usually referred to as Simulcasting or Restreaming, but it's also known as Live Syndication, Rebroadcasting, and RTMP Passthrough (it really depends on who you ask, but it should become obvious which name we like best).

Popular internet personalities use simulcasting to reach all of their loyal fans across social networks with a single stream. News organizations use it to publish a stream on their own website as well as their Facebook page. There's a handful possible uses of simulcasting but the goal is always to reach a wider audience.

The Mux Video API makes it easy for developers to build live streaming into their applications, and with the new Simulcasting feature developers can now let their users publish live streams on social platforms. Cool, right? Combine simulcasting with existing features like Persistent Stream Keys and Automatic Live Stream Recording and the API becomes pretty great for social sharing apps and other user-generated content.

Live streaming simultaneously across multiple platforms.

LinkThe Details

Simulcast Targets can be used for any platform that supports the RTMP or RTMPS protocol, which includes, but isn't limited to:

  • Facebook Live (but not Instagram 😢, where you can only go live from the Instagram app)
  • YouTube Live
  • Twitter Periscope
  • Twitch
  • Crowdcast
  • Vimeo

To add simulcasting to a live stream, you can simply add a Simulcast Target for each additional platform the stream should be pushed to. You can do this when the Live Stream object is first created, or anytime afterwards, however they can only be added while the Live Stream object is not active.


{ "playback_policy": [ "public" ], "new_asset_settings": { "playback_policy": [ "public" ] }, "simulcast_targets" : [ { "url" : "rtmp://", "stream_key" : "12345", "passthrough" : "Youtube Example" }, { "url" : "rtmps://", "stream_key" : "12345", "passthrough" : "Facebook Example" } ] }

LinkAvailability & Pricing

Simulcasting has an added cost on top of live streaming, but like all of our pricing, you only pay for what you use. See the pricing page for details.

There's a limit of 6 simulcasts/restreams per live stream. Let us know if you have a use case that requires more.

Give Simulcast Targets a shot and let us know how you like it!

Written By

Steve Heffernan

Steve Heffernan – Co-founder and Product Architect

Creator of Video.js and co-founder of Zencoder. Semi-professional drummer and apparently drove a Civic lowered more than Mux's live latency in high school.

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