From the Streaming CDN team. The original, kept up to date, is at streaming-cdn.ewin888.com/guides/webrtc-vs-hls-live-streaming-latency.
HLS and DASH cut a live stream into segments of a few seconds and the player buffers several of them before it starts, so viewers usually watch several seconds or more behind the camera. Low-latency variants shrink that, but the design is still built on files and buffers. WebRTC sends media continuously as packets over a real-time connection, so end-to-end delay is measured in hundreds of milliseconds.
Side by side
| HLS / DASH | WebRTC | |
|---|---|---|
| Typical delay | Several seconds and more | Low hundreds of milliseconds |
| How media travels | Segment files over HTTP, buffered | Continuous packets over a real-time connection |
| Browser playback | Through a player library (native in Safari) | Native in every modern browser |
| Interaction in the same moment | Viewers react to what happened seconds ago | Host and viewers interact in the same second |
| Weak networks | Switches renditions between segments | Simulcast: several quality levels at once, each viewer gets what their line can carry |
When the seconds matter
- Live chat, Q&A and votes: a host answering a question that is already ten seconds old breaks the conversation.
- Live commerce and auctions: bids and flash-sale stock have to match the picture.
- Sports and esports: with in-play predictions or bets, a viewer who is seconds behind learns the result from a faster source first.
- Remote monitoring: operators watching vehicles, tables or sites need the picture as it is now.
- Classes and coaching: a teacher's question and a student's answer must meet in real time.
When HLS is still fine
One-way broadcasts where nobody interacts, and on-demand video, do not gain much from shaving seconds; plain HTTP delivery and long caches work well there.
WebRTC delivery without building it
Running WebRTC at scale means media servers, TURN relays, simulcast, reconnects and a delivery network close to viewers. Streaming CDN does that part:
- Publish from OBS over WHIP, RTMP or SRT encoders, or relay an existing RTSP, RTMP or HTTP-FLV stream.
- Viewers watch over WebRTC in the browser, through a network in more than 130 countries and territories, with nothing to install.
- Chat, votes and live data travel on real-time data channels in step with the picture.
- Signed playback URLs, Referer/Origin allowlists and request-source policies keep the stream on your own pages.
- Usage is measured per customer, stream and domain for billing.
Streaming CDN delivers live video to browsers over WebRTC, with chat and votes on real-time data channels, adaptive quality, recording and playback protection. Learn more.
