RTMP is the protocol that carries your stream from OBS to Twitch, YouTube, and every other platform. Understanding it helps you troubleshoot stream issues and optimize your setup with tools like StreamTranslate.
Try StreamTranslate FreeReal-Time Messaging Protocol (RTMP) is a TCP-based protocol originally developed by Macromedia (later Adobe) for transmitting audio, video, and data between a streaming encoder like OBS and a media server like Twitch or YouTube's ingest infrastructure. Despite being decades old, RTMP remains the dominant standard for live stream ingest in 2026.
When you click "Start Streaming" in OBS, the software encodes your video and audio into a compressed stream (typically H.264 video and AAC audio) and pushes it to a streaming server via RTMP. The RTMP connection is persistent — it maintains an open connection for the duration of your stream rather than sending individual files or requests.
RTMP operates on port 1935 by default. Most streaming platforms also support RTMPS (RTMP over TLS/SSL) on port 443, which encrypts the stream data in transit for additional security. Twitch, YouTube Live, Facebook Gaming, and Kick all accept RTMP ingest from standard streaming software.
RTMP is specifically the ingest protocol — the one-way pipe from your encoder to the streaming server. It's not what your viewers use to watch your stream. Viewers receive streams via HLS (HTTP Live Streaming) or DASH (Dynamic Adaptive Streaming over HTTP), which are delivery protocols optimized for consumer playback devices.
Newer ingest alternatives like SRT (Secure Reliable Transport) and WHIP (WebRTC-HTTP Ingest Protocol) are gaining traction for use cases requiring lower latency or better reliability over poor network conditions. However, RTMP remains universally supported across all major streaming platforms and all major streaming software including OBS, Streamlabs, XSplit, and Twitch Studio.
StreamTranslate integrates with your stream via an OBS browser source, not by intercepting or proxying your RTMP stream. This means your RTMP setup remains completely unchanged — StreamTranslate simply adds caption and translation overlays on top of your existing stream configuration without adding any latency to the RTMP pipeline itself.
OBS and other encoders use RTMP to push your encoded stream to Twitch, YouTube, Kick, and other platforms in real time.
StreamTranslate works via OBS browser source and doesn't touch your RTMP configuration — your existing stream setup works unchanged.
RTMP uses port 1935 by default. RTMPS (encrypted) uses port 443 for secure ingest supported by most major platforms.
RTMP (Real-Time Messaging Protocol) is a TCP-based protocol for transmitting audio and video between a streaming encoder and a server in real time.
StreamTranslate works via an OBS browser source that captures audio directly, without needing to intercept or proxy your RTMP stream.
RTMP is for ingest (encoder to server) while HLS is for delivery (server to viewer). OBS uses RTMP to push your stream, viewers receive it via HLS.
RTMP uses port 1935. RTMPS (secure RTMP) uses port 443 for encrypted transmission supported by most major streaming platforms.
RTMP ingest remains the dominant standard. Newer alternatives like SRT and WHIP are gaining adoption but RTMP is universally supported and will remain relevant for years.