YouTube Live Streaming supports the following ingestion protocols for third-party clients:
| Ingestion Protocol | Encrypted | Video Codecs Supported | Comment |
|---|---|---|---|
| RTMP | No | H.264 | Suitable for normal, low, or ultra-low latency live streaming. |
| RTMPS | Yes | H.264 | Suitable for normal, low, or ultra-low latency live streaming. |
| HLS | Yes | H.264, H.265 (HEVC) | Better for 4K resolution because of HEVC support. Supports HDR. Not suitable for ultra-low latency. |
| DASH | Yes | H.264, VP9 | Better for 4K resolution because of VP9 support. Not suitable for ultra-low latency. |
Real Time Messaging Protocol (RTMPS) is a widely-used protocol for video streaming that YouTube Live has accepted since the service began.
Real Time Messaging Protocol Secure (RTMPS) is a secure extension to RTMP. RTMPS benefits both content creators and viewers by preventing man-in-the-middle attacks on the ingestion side of livestreams. This ensures that all of a creator's live streaming data—including video, audio, and control signals—is securely transmitted to YouTube's servers, protecting it from tampering or interception in transit.
The HTTP Live Streaming (HLS) and Dynamic Adaptive Streaming over HTTP (DASH) ingestion protocols are also encrypted, like RTMPS. They also support codecs that RTMP and RTMPS don't. Next-generation video codecs such as VP9 and High Efficiency Video Coding (HEVC) can offer much better compression relative to H.264, allowing users to either stream with higher quality for a given bitrate or stream with the same quality while using a lower bitrate, which could decrease buffering. This makes HLS or DASH ingestion a good choice for premium content that requires higher quality and higher resolution, albeit at a relatively higher latency. Note that HLS and DASH ingestion typically incur greater latency than RTMP because HLS and DASH are segment-based.