How to multistream with OBS: a restream service or a plugin

The short version

There are two ways to send your OBS stream to several platforms at once. A restream service such as Restream takes one stream from OBS and sends it on to each platform from its own servers, so your upload carries one stream. A multistream plugin in OBS, such as the free Aitum Multistream, sends each platform its own stream from your computer: each can have its own settings, and each takes its own share of your upload.

	Through a restream service	With a plugin in OBS
Upload from your computer	One stream, however many platforms	One stream per platform, added together
Settings per platform	Every platform gets the stream you send; changing it for one is Restream’s paid Transcoding add-on	Each output has its own bitrate, encoder and audio tracks
Work for your computer	One encode	One more encode for each output with different settings
Cost	A free plan for two platforms at once; more need a paid plan	Aitum Multistream and Multiple RTMP outputs are free

Choose the service when your upload is the limit. Choose a plugin when each platform needs different settings, or when a vertical stream for TikTok or YouTube goes out beside a horizontal one. Twitch’s Enhanced Broadcasting is a case of its own: it goes straight from OBS to Twitch, and the other platforms get a second stream (see Twitch below).

Work out the upload first

Every stream that leaves your computer needs its own video and audio bitrate, plus the margin its platform asks for. The platforms a restream service adds cost you nothing more, because the copies are made on its servers.

Example: Twitch at 1080p and 60 fps and YouTube at 1080p and 30 fps, each straight from OBS in H.264. Twitch: (6 + 0.096) × 1.30 = 7.92 Mbps, because Twitch asks for upload equal to the stream’s bitrate plus 30%. YouTube: (14 + 0.128) ÷ 0.80 = 17.66 Mbps, keeping free the 20% of upload that YouTube recommends. With 2 Mbps for the rest of the house, that is 27.58 Mbps.

The same two platforms through a restream service, at Twitch’s 1080p60 settings: (6 + 0.096) × 1.30 + 2 = 9.92 Mbps, however many platforms the service sends it to. 6,000 kbps is also YouTube’s minimum for 1080p60 in H.264 and sits inside Kick’s range (1,000 to 8,000 kbps) and Facebook’s (4,500 to 9,000 kbps), so each of them takes the same stream.

The upload calculator does this sum with your own upload: one platform, a restream service, or two platforms straight from OBS.

Option 1: a restream service

Restream is in OBS’s own list of services. Add the platforms you want under Channels in Restream. Then in OBS open Settings, Stream, choose Restream.io as the service and press Connect Account, or paste the stream key of a new Encoder (RTMP) stream from Restream. Press Start Streaming in OBS, and the stream goes live on every channel you turned on in Restream.

Restream sends each platform the stream it receives, so choose settings every one of them accepts: Restream asks for strict CBR and a 2-second keyframe interval, and points you to each platform’s own figures. Lowering the quality for one platform only is Restream’s Transcoding add-on, bought by the hour and not part of any plan, which goes up to 1080p at 60 fps and 6,000 kbps. Restream’s free plan multistreams from OBS to two platforms at once; reaching more at once needs a paid plan.

Option 2: a multistream plugin in OBS

A plugin adds outputs to OBS, one for each extra platform, each with that platform’s server and stream key; OBS’s own Stream settings still send the main stream. Aitum Multistream is free and says plainly that it is not a cloud relay: each extra output uses your computer and your upload, and each can have its own encoder, bitrate and audio tracks. The Multiple RTMP outputs plugin can also share OBS’s own encoder with an extra output, which saves processor work when both platforms take the same settings.

Give each output its own platform’s settings: the published figures for Twitch, YouTube, Kick and Facebook are on their pages here. Each output with different settings is one more encode for your graphics card or processor, so rehearse with every output running before a long stream.

Streamlabs Desktop and Meld Studio build multistreaming in instead of a plugin; on Streamlabs, more than one landscape platform needs its paid Ultra plan. Streaming software compared has the details.

Twitch: its multistreaming rules and Enhanced Broadcasting

Twitch allows multistreaming under its Simulcasting Guidelines, with two conditions. Your stream on Twitch must not be worse than on the other platforms: Twitch’s example is shrinking or otherwise degrading the video on Twitch. And Twitch must not be used to send viewers to your live stream elsewhere: no links, banners, QR codes, stream titles, go-live notifications or chat commands that point to it. Links to your other channels in your bio or panels are allowed. The guidelines apply to every streamer unless you have an exclusivity agreement with Twitch, and Twitch sends a warning before it takes any action.

Enhanced Broadcasting, which Twitch needs for 2K and Dual Format, goes straight from OBS to Twitch and sets its own bitrate: up to 10.5 Mbps in total, or the upload Twitch lists for 2K and Dual Format. Twitch says you can still send a second stream to a restream service for your other platforms at the same time: send it from a plugin output, and add its upload to Twitch’s. For 2K, Twitch advises setting Maximum Video Tracks to 3 or 4 when you simulcast (Settings → Stream → Multitrack Video), so the encoder isn’t overloaded. Each mode’s upload and how to turn it on are on the Twitch settings page.

On Kick, a stream sent to other platforms at the same time pays 50% of the usual Partner revenue, by Kick’s Partner page.

Horizontal and vertical at once

The Aitum Vertical plugin adds a second, vertical canvas to OBS, with scenes of its own that you can link to your normal scenes so the two switch together. It runs on Windows, macOS and Linux. What you do next depends on where the vertical stream goes.

To Twitch, beside your horizontal stream: that is Twitch’s Dual Format. Turn on Enhanced Broadcasting in OBS’s Stream settings and choose Aitum Vertical as the Additional Canvas. Twitch’s vertical canvas is 1080 × 1920, and at 1080p Twitch asks for 12.5 Mbps of upload with added transcode support, 13.5 Mbps without.
To TikTok, YouTube or another platform, as its own stream: with Aitum Vertical installed, add a Vertical Output for each service in Aitum Multistream’s settings. It is one more stream from your computer, so its upload adds to the horizontal one. Going LIVE on TikTok from OBS needs a stream key from TikTok: see how to go LIVE on TikTok from a computer.

Rehearse with every output running

Before a long stream, test with every output running at once: Twitch’s bandwidth test (add ?bandwidthtest=true to the end of your stream key), which doesn’t show your channel as live, and a private or unlisted YouTube stream. Watch each platform on another device, with sound. If one stutters, OBS’s stats tell a slow connection from an overloaded computer.

Questions

Does multistreaming need a faster computer? Not through a restream service: OBS encodes one stream. With a plugin, each output with its own settings is another encode, and Enhanced Broadcasting already encodes several qualities on your graphics card, so rehearse with everything running.

Can I read chat from every platform in one place? Restream Chat combines it. Twitch’s guidelines allow tools that combine chat from other platforms for your own use.

Can Twitch Affiliates and Partners multistream? Yes, under the same Simulcasting Guidelines, unless their agreement with Twitch requires exclusivity.

Which bitrate suits every platform through a restream service? At 1080p and 60 fps, 6,000 kbps: Twitch’s own figure, YouTube’s minimum in H.264, and inside Kick’s and Facebook’s ranges.

How to multistream from OBS