How jitter is measured here
Before the speed tests, your browser sends 21 small requests to the test server while the connection is idle. Jitter is the average difference between each round-trip time and the one before it. If ping goes 20, 22, 21, 35, 20 ms, the differences are 2, 1, 14 and 15 ms, so jitter is 8 ms.
This is close in spirit to the jitter figure voice and video apps calculate (defined in the RTP standard, RFC 3550), but it is not identical. Apps measure jitter on their own audio and video packets during a call, which can show different values from a short test.
What jitter level is a problem?
| Jitter | What to expect |
|---|---|
| Under 10 ms | Very steady. Calls and games should be smooth. |
| 10–30 ms | Usually fine. Apps buffer a little to smooth it out. |
| Over 30 ms | Choppy audio, frozen video frames and inconsistent game feel become more likely. |
As a reference point, Microsoft’s guidance for Teams targets packet jitter under 30 ms.
Why jitter hurts live apps
Calls and games send a steady stream of small packets. The receiving app expects them at regular intervals. When some arrive late, the app must either wait (adding delay) or carry on without them (causing gaps). Streaming video avoids this by loading several seconds ahead, which is why Netflix can play smoothly on a connection that makes calls unusable.
Common causes of jitter
- WiFi interference from neighbors’ networks, microwaves, Bluetooth and distance from the router.
- Competing traffic on your own connection, like a download or backup.
- Congestion on your provider’s network at busy times.
- Mobile networks, where signal and cell load change constantly.
To tell these apart, test on a cable with nothing else running. If jitter drops, the cause is inside your home. Our guide on reducing jitter takes you through the fixes.