Teams or Zoom stuttering? The 7 real causes and their fixes
"You're breaking up." "Your video froze." Anyone working from home knows the frustration. The reflex is to buy a faster internet plan, but that rarely solves anything: a video call only uses 1.5 to 4 Mbps — even the cheapest plan covers that easily. The problem is almost always the quality of the connection, not the speed. Here are the seven real causes, in order of likelihood.
1. WiFi
By far the biggest culprit. WiFi signals are disrupted by walls, microwaves, neighboring networks and even baby monitors. Every disruption means a retransmitted packet, and that means jitter — irregular arrival times you hear as robotic audio. Fix: connect your work computer with an ethernet cable. If that is truly impossible, use the 5 GHz band and move closer to the router.
2. Bufferbloat
If someone downloads while you are on a call, your router can queue up packets and your latency explodes. Read our article on bufferbloat for the explanation and the fix (Smart Queue Management).
3. Upload saturation from cloud sync
OneDrive, Google Drive, Dropbox and photo backups often upload in the background — and your camera feed has to squeeze through that same, much smaller upload pipe. Fix: pause sync during important calls, or set bandwidth limits.
4. An overloaded or outdated router
Routers five years or older handle modern traffic from dozens of devices poorly. Restart your router weekly and consider replacing it if it is older than five years.
5. Packet loss on the line
Lost packets literally mean dropped words. More than 1–2% loss makes calls audibly worse. A faulty cable, a bad coax connection or an outage at your provider are the usual causes. Our stability test measures for five minutes whether your line loses packets.
6. VPN detours
A corporate VPN routes all your traffic through a company server first. If that server is far away or overloaded, your latency can double. Ask IT whether call traffic can bypass the VPN (split tunneling) — most organizations allow this by now.
7. The computer itself
Background virus scans, too many browser tabs or an overloaded laptop cause stutters that look like a network problem. Check your CPU usage during a call: above 80% means the problem is your device.
Find your cause in 20 seconds
Our Video Call Test simulates a real call: data up and down simultaneously at realistic bitrates while we measure latency live. The result tells you per scenario (1-on-1, group call, screen sharing, webinar) whether your connection can handle it — and what the bottleneck is if not. Test over WiFi first, then over a cable: the difference between the two usually points straight at the culprit.