What Is Simulcasting? Meaning, Rules and Setup

What simulcasting means

Simulcasting means broadcasting the same live video to more than one place at the same time. Twitch's own help center defines it in these words: "Simulcasting, or multistreaming, refers to the act of broadcasting the same stream to multiple platforms at once." In streaming, simulcast, multistream and multistreaming are used for the same thing, and what is multistreaming explains the three ways to do it. This page is about the term and about the rules that come with it.

Simulcast, multistream, restream: the words

Platform rules to check before you simulcast

Each platform sets its own rules. The one we found with published simulcast guidelines is Twitch. Its Terms of Service (section 11) say that while you are streaming live on Twitch you may simultaneously live stream on another service that supports live streaming of user generated content, only if:

• the quality of Twitch users' experience of your simulcast is, at a minimum, no less than the experience on other platforms, including your engagement with the Twitch community, for example in chat;
• you do not provide links, or otherwise direct your community, to leave Twitch for your simulcast on other services; and
• you do not use third-party services that combine activity from other platforms on your Twitch stream during a simulcast, such as merging chat.

Twitch's Simulcasting Guidelines FAQ adds that these guidelines apply to all streamers unless you have an agreement with Twitch that requires exclusivity, and that you can list your presence on other platforms in your bio but cannot actively encourage viewers to leave Twitch for a concurrent livestream elsewhere. Twitch has a warning step before enforcement, according to the same FAQ. We quote the Terms as we reviewed them on October 5, 2026; Twitch updates its policies, so read the current text, and check any exclusivity terms in your own agreements. This is not legal advice.

Instagram's Live Producer announcement says simulcasting is not natively supported, but that you may use streaming software that allows simulcasting and add Instagram Live as a custom RTMP endpoint. See Instagram stream key for what it says. We did not find comparable simulcast rules on the YouTube, Facebook, Kick or LinkedIn pages we reviewed, so this page states none for them; check each platform's terms.

What simulcasting costs your connection

If your encoder sends a separate copy to every destination, upload use multiplies. For example, three destinations at 6,000 kbps video plus 128 kbps audio need about 6.128 × 3 = 18.4 Mbps of upload, before headroom. If you send one stream to a relay and the relay does the copying, your upload stays near 6.1 Mbps. The bandwidth calculator does this arithmetic for your own numbers, and bandwidth and bitrate requirements explains the headroom.

A simulcast checklist

1. Read each platform's current rules, starting with Twitch's Simulcasting Guidelines if Twitch is a destination.
2. Get each platform's server URL and stream key (see stream keys by platform).
3. Choose encoder settings that every destination accepts, such as H.264 video, CBR and a 2-second keyframe interval (see the bitrate recommender).
4. Decide how you will read chat from every platform in one place.
5. Test with a private or unlisted stream first.

Sources

• Twitch Help: Simulcasting Guidelines FAQ
• Twitch Terms of Service, section 11 (Simulcasting)
• Instagram: Live Producer (published November 2, 2022)

Platform figures were checked on October 5, 2026. Platforms change their recommendations, so confirm against the current documentation before you go live.