SRT support lands in Stream as a translation layer for RTMP workflows

Cloudflare Stream now accepts SRT (Secure Reliable Transport) as an ingest and output protocol, available in open beta. SRT is a UDP-based video transport protocol designed as a modern alternative to RTMP, which has been effectively unmaintained since 2012. SRT offers lower latency, resilience to packet loss on unpredictable networks, support for modern codecs, and built-in handling for captions and multiple audio tracks.

For broadcasters and platforms, the protocol gap has been a classic adoption standoff: platforms won’t support a protocol no client uses, and clients won’t implement a protocol platforms don’t accept. Cloudflare is positioning Stream Connect as the intermediary, translating between SRT and RTMP in either direction. This lets broadcasters use SRT for last-mile reliability while still pushing to RTMP-only destinations, and lets platforms accept SRT inputs while keeping legacy RTMP client compatibility. Translation is priced at $1 per 1,000 minutes, independent of encoding settings.

SRT can also be used directly with Stream Live as an ingest protocol, producing HLS and DASH manifest URLs for end-to-end live streaming and simulcasting. The implementation supports adding or removing RTMP or SRT outputs mid-stream without restarting the source, scales to tens of thousands of concurrent streams per customer, and runs across Cloudflare’s global server footprint.

Why SRT avoids the TCP bottleneck

RTMP carries video over TCP, which enforces strict packet ordering and reliable delivery. That works well in general, but it introduces a well-known problem for live video: head-of-line blocking. If a single packet is lost—common on mobile networks and Wi-Fi—the entire connection stalls while that packet is retransmitted, holding up every frame that follows it.

SRT, built on UDP, sidesteps this by implementing its own reliability layer on top, similar in spirit to QUIC. It applies selective packet recovery tuned for low-latency video: if a lost packet isn’t recovered quickly, the stream moves on rather than halting, because a single dropped frame is rarely noticeable to the viewer. The result is fewer buffering events and lower latency, especially for broadcasters on poor connections.

Getting started

SRT is already supported in common broadcasting tools like OBS and FFmpeg. To go live via SRT, set up a live input on Cloudflare Stream and configure your encoder with the SRT URL and stream key provided. Existing RTMP-based workflows can be preserved by using Stream Connect as a protocol gateway, removing the need to wait for upstream platforms to adopt SRT natively.

Cloudflare says it is exploring support for additional media protocols beyond RTMP and SRT.