Teams video freezing but your speed test is fine: how to find the cause

A speed test fills the line with a few large transfers and reports how much it carried. A video call is the opposite: a thin, constant stream of small packets, each of which has a deadline. If a packet is late, the picture stalls, and if it never turns up Teams has to guess or wait.

So a line can pass a speed test and still freeze a call. The usual culprits are delay that swings (jitter), packets that go missing, a router queue that fills when the line is busy, weak Wi-Fi, a VPN, or a laptop that cannot keep up with encoding video. Our Teams speed test guide lists Microsoft’s bandwidth figures. This page assumes the bandwidth is fine and goes looking for the instability.

Teams has a built-in readout of what your call is experiencing. Open it while the video is frozen, because it is a live view and not a history.

1. In the meeting controls, select More actions, then Settings, then Call health (Microsoft’s instructions).
2. Wait at least 15 to 30 seconds into the problem. Microsoft says the figures update every 15 seconds, so shorter glitches may not show.
3. Read the network figures first: round-trip time and received packet loss. Then check the audio section for received jitter.
4. Take a screenshot, including the time, so you can compare a bad moment with a good one.

NetCheckPro does not measure packet loss, because a browser cannot send the packets that measuring loss needs. For loss during a Teams call, the received packet loss figure in Call health is the better evidence. Our jitter vs latency vs packet loss guide explains how the three differ.

Key Call health figures such as received packet loss and received jitter describe what you receive, while sent bitrate and frame rate describe what you send (source). Two people on the same call can therefore see different things, and knowing which direction is failing tells you where to look. Microsoft’s call-quality dashboard also treats outgoing and incoming streams separately, because that shows which leg of a call was poor (source).

This one test separates the two most common causes. Plug the laptop into the router with a cable, switch Wi-Fi off, and rejoin a call or a test meeting with a colleague.

• Fine on Ethernet, freezes on Wi-Fi: the problem is the wireless link. Move closer, use the 5 GHz band, and avoid extenders. Microsoft notes the 2.4 GHz range is often affected by other consumer devices, while 5 GHz suits real-time media better (source). Our Wi-Fi stability test shows whether delay varies more on wireless.
• Still freezes on Ethernet: the problem is the router, the line, the app or a VPN, so keep going down this page.

Run the test above on both connections. A jump in jitter on Wi-Fi alone is strong evidence. If you cannot run a cable, say so when you report the problem, because it changes who can help.

If the network is the cause, joining the same meeting from the same computer through the Teams web client should freeze too. If the browser version is smooth and the desktop app is not, the network is probably not the problem, and the app, its cache, your graphics or camera driver, or a struggling processor is more likely.

1. Join the same meeting on the same connection through the web client and compare.
2. Update the Teams app and restart the computer, which clears most stuck states.
3. Update the graphics and camera drivers, and try a different camera if you have one.
4. Close heavy apps. Microsoft’s admin guide treats system CPU use under 80% as healthy and notes that when Teams falls back to software video encoding, a weak processor can degrade performance (source).

If freezing follows you from device to device on the same network, the device is not the cause.

If calls break when a backup, game download or someone’s video fills the line, suspect a router queue. Your call packets wait behind the bulk traffic, and the delay shows up as jitter and freezing even though the speed figure is fine. This is bufferbloat.

Our bufferbloat test compares your latency at rest with your latency while the line is busy. The full explanation and fixes are in why ping is high when someone is streaming or uploading. If your upload is the weak link, see the low upload speed fix guide too.

A work VPN is a frequent hidden cause. Microsoft recommends that Teams traffic bypasses a VPN, called split tunnelling, for several reasons: VPNs are not usually built for real-time media, some do not support UDP, they add another layer of encryption, and traffic hairpinned through a VPN device can reach a more distant Teams entry point and add latency and jitter (source).

If your employer allows it, compare a call with the VPN on and off using the VPN on vs off test. If the VPN is required, ask IT whether Teams media can be split out. That is a policy decision for them, not a setting you should change yourself.

“Teams freezes” is hard to act on. A short report with evidence gets escalated faster. Include:

• The date, the time and how long the freeze lasted, and whether it happens every day or only at certain times.
• Wired or Wi-Fi, and whether Ethernet changed anything.
• Desktop app or web client, and whether the other one behaves differently.
• A screenshot of Call health during the freeze: round-trip time, received packet loss and received jitter.
• Whether the problem was incoming, outgoing or both, and what other participants saw.
• Whether the VPN was on, and whether turning it off helped.
• A NetCheckPro result taken during the freeze: idle latency, jitter and the bufferbloat grade. Its latency and jitter come from 26 round trips to a nearby Cloudflare server, not from Teams’ own servers, so treat it as supporting evidence. See how we measure for the limits.

An ISP can act on clean evidence from a cable connection, and IT can act on specific Call health numbers and times. If Call health looks clean while video still freezes, that points away from the network and towards the device or the Teams client, which is useful to know too. For a pattern across many users, see the business internet audit. If you need the jitter basics first, read how to fix high jitter.