Webinars & macOS/iOS Power Saving Modes

How macOS and iOS power saving modes impact webinar broadcasting

Modern devices like those running macOS and iOS are equipped with features designed to extend battery life, such as "Low Power Mode" and "Optimize Video Streaming While on Battery." While these options are fantastic for general use, they can have unintended consequences during resource-intensive activities like webinar broadcasting.



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In this article, we'll explore why webinar hosts and attendees might experience freezing video or lagging audio when these modes are enabled and provide practical tips to mitigate these issues.

How power saving modes affect WebRTC performance

Webinars rely heavily on WebRTC (Web Real-Time Communication), a protocol designed for transmitting video and audio in real time. WebRTC typically uses the UDP protocol, which is more resource-intensive than alternatives like TCP. While UDP ensures minimal latency, it requires substantial computing and network resources to maintain high-quality audio and video streams.

When Low Power Mode or Optimize Video Streaming is enabled, several factors come into play:

» For webinar hosts

Video quality drops

If a host's MacBook is running on battery (especially below 50%), the power-saving settings throttle both CPU and network usage.
This throttling can lead to:

Video "artifacts" (e.g., pixelated or blocky images).
Freezing or jerky video streams.

Audio issues

Audio may start to stutter, lag, or become desynchronized with the video.

Increased latency

The browser struggles to maintain consistent real-time transmission, impacting the overall webinar experience.

» For webinar attendees

Hardware decoding limitations

Not all macOS and iOS devices support hardware-accelerated video decoding for all browser versions. Without hardware acceleration, the CPU must decode video streams, which consumes more power and slows down performance.

Throttled performance

With power-saving options enabled, the device deliberately reduces performance to conserve battery, affecting how quickly the browser processes incoming audio and video data.

Useful tips for webinar hosts

To ensure smooth broadcasting, hosts should consider the following recommendations:

Keep the device plugged in

Whenever possible, connect your MacBook or iPhone/iPad to a power source during the webinar. This prevents power-saving modes from activating and ensures optimal performance.

Close unnecessary applications

Shut down all non-essential apps and background processes. This reduces overall CPU usage, leaving more resources for the browser and WebRTC to operate efficiently.

Monitor battery levels

Avoid hosting webinars when the battery is critically low (<50%). Devices under low-battery conditions may throttle performance even if power-saving modes are turned off.

Test your setup

Before starting the webinar, test your camera, microphone, and network stability under the same conditions you’ll use during the broadcast. This can help identify potential issues early.

Useful tips for webinar attendees

Optimize playback

If you experience freezing or lag, try closing unnecessary tabs and apps. This can free up system resources for video playback.

Use headphones

Headphones with a built-in microphone often perform better than built-in laptop speakers and microphones, especially when the device is under stress.

Check device settings

Disable Low Power Mode or similar settings during webinars to allow the device to operate at full performance.

Update your browser

Make sure your browser is up to date, as newer versions often include optimizations for WebRTC and hardware acceleration.

Conclusion

Webinar broadcasting is a demanding task for any device, particularly when running on battery power. macOS and iOS power-saving features, while beneficial in many scenarios, can inadvertently degrade the quality of real-time communication. Hosts should prioritize using plugged-in devices and minimizing resource usage, while attendees can improve their experience by optimizing their device settings.

By following these tips, both hosts and attendees can ensure smoother webinar sessions, even when power-saving features are in play.

Updated on: 09/01/2025