Lag on video calls is caused by high latency, jitter, or packet loss on your network. To fix it: switch from Wi-Fi to Ethernet for an immediate improvement in stability. If you must use Wi-Fi, move closer to your router and use the 5GHz band instead of 2.4GHz. Close bandwidth-heavy apps — cloud backups (Dropbox, OneDrive sync), streaming video, and large downloads all compete with your call. In your video app, reduce video quality: in Zoom go to Settings > Video and uncheck HD; in Teams, click the three dots during a call and choose "Turn off incoming video" if bandwidth is limited. Restart your router if lag started suddenly. If lag persists, run a network test to measure latency, jitter, and packet loss — if jitter is above 30ms or packet loss above 1%, contact your ISP.
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