Steam broadcast video specs & encoding settings
22 Jun 2026 · 5 min read
Steam Store Broadcasts run over RTMP, and Valve says that for external streaming software "Steam requires these encoding specs to be set." Here they are, field by field, from Valve's setup guide.
The short version
Resolution & frame rate
Valve lists the frame rate as 30 FPS or 60 FPS and the frame ratio as 16:9. Steam transcodes for viewers on its side: once an upload session has more than 10 concurrent viewers, a 1080p input will likely also get 720p, 480p and 360p versions, per Valve's viewership statistics guide.
Bitrate: keep it constant
Valve's maximum video bitrate is 7000 kbps CBR. If your stream is interrupted often, Valve says to check your broadcast history for this error: "Make sure your upload key-frame interval is set to 2 seconds and use constant bitrate (CBR). Limit your encoders group of picture (GOP) to at most two times your framerate."
Keyframe interval (GOP)
Set a keyframe every 2 seconds. Valve's OBS steps put it plainly: "This step is important. Without this setting your stream will fail to start."
Audio
Encode audio as AAC-LC at no more than 128 kbps. One software note from Valve: vMix defaults to profile Main and level 3.0, and "You must change those settings in order for VMIX to stream correctly to Steam."
Sources: Setting Up A Stream, Broadcast Viewership Statistics. Checked 31 Oct 2026. Valve updates these pages; the Steamworks docs always win.
What video should I upload?
Any 16:9 trailer, gameplay capture or sizzle reel works. Longer loops feel more “live” than a 30-second clip on repeat. Lead with your strongest footage in the first minute.
Let Loopcast handle it
With Loopcast you don’t set any of this by hand. We transcode whatever you upload to Steam’s exact broadcast spec automatically, so it’s accepted every time. All you need is your Stream key.