In this article:
What is latency?
The latency of a live event is the delay between your production service and your audience.
When you share content or speak during your event, there's a delay before the content or what you're saying reaches the audience. That delay is called latency. Lower latency has less of a delay, but as a result, the video quality may be slightly lower. Higher latency has a longer delay, but the video quality is better.
Stream latency varies greatly depending on network connection speed and stream health (bitrate, resolution, etc.) but the average latency for streams on Vimeo Live is about 15 seconds unless you enable low-latency streaming or fail-safe streaming.
When it comes to streaming latency, there are three factors to consider: quality, bandwidth, and CPU usage. Each of these aspects is directly related. For example, having higher quality means higher bandwidth and CPU usage is required in order to decode the data.
Achieving a high-quality and low-latency stream would significantly increase the bandwidth and CPU usage for each of your viewers. In achieving a lower impact for audience members, and subsequently improving the average viewing experience, Vimeo makes a trade-off for slightly higher latency which allows for better compression of the data. Having more time to compress the data reduces CPU usage and bandwidth requirements significantly.
In short, we make trade-offs in order to ensure viewers in all areas of the world—viewers who may have a wide range of devices and bandwidths—can view the content smoothly, even if it's a few seconds behind.
What is the expected latency of my live event?
The latency of your event will depend on which setting you selected when setting up your event. This can also be edited on the event settings page after you have created your event. Low latency will have slightly lower quality, but the shorter delay will make things go more smoothly if you're planning to have a lot of audience interaction — like asking your audience to respond to you in the chat.
Go to Settings > Production > Latency to find the below options:
Learn more at Enable low-latency streaming.
- 5-7 second delay
- Best for real-time audience interaction
This is the default selection for live events.
- 15-20 second delay
- Best for high-quality viewer playback
Learn more at How to stream to your event with fail-safe streaming.
- 60-70 second delay
- Best for overall reliability and stability