If you use Comcast Xfinity internet, your FaceTime calls might be about to get better. Instead of bumping up the amount of data that your internet connection can send or receive at one time (usually called bandwidth or throughput), a new upgrade is coming to reduce the amount of time it takes for each packet of information to make the trip.
Comcast is officially starting to roll out the “pioneering new, ultra-low lag connectivity experience” to cities including Atlanta, Chicago, Colorado Springs, Philadelphia, Rockville (in Maryland), and San Francisco. (Disclosure: Comcast is an investor in Vox Media, The Verge’s parent company.)
The technology powering this upgrade is based on a standard called L4S, which stands for “Low Latency, Low Loss, Scalable Throughput.” My former colleague Mitchell Clark has a thorough explainer of what L4S is supposed to do, but the intention is that the tech can significantly reduce latency so that things like video games are smoother and video calls feel more like talking in real life without awkward delays and pauses.
L4S pulls this off by giving internet packets an indicator that lets them know if they’ve run into congestion or queueing along any of the hops in their trip between a user and whatever they’re connecting to. If there is a delay, then the devices can start to adjust to stop making the congestion worse — and possibly eliminate it entirely.
As Mitchell explains, it can’t bend the laws of physics to make data travel faster than the speed of light, but it can reduce the extra delays in the middle that have been slowing your connections down. While the bandwidth upgrades we’ve seen over the years from dial-up to broadband have increased the amount of information transmitted, this change will actually make the internet feel faster for once.
Comcast says that you’ll initially see the low-latency improvements with FaceTime, Nvidia’s GeForce Now, “many games” on Steam, and “apps on Meta’s mixed reality headsets that will support this technology.” Apple, Nvidia, and Valve all collaborated with Comcast during its trials of the technology, and Apple has had support for L4S built into its devices since iOS 17 and macOS Sonoma.
Comcast also notes that the tech will “expand to any additional content and application providers who choose to leverage the new open standard technology for their own products.”
I haven’t tried the tech myself, so I can’t personally speak to how the latency improvements feel in practice. But according to Comcast spokesperson Joel Shadle, during the trials, “we were able to reduce our working latency – the latency under normal conditions in the home when people are using the Internet – by 78 percent,” meaning that Comcast customers “should expect to see significant improvement.”
When it’s “fully deployed,” Comcast says its low-latency tech will be available to “all Xfinity Internet customers.”
