Jitter Test
Measure how much your latency swings from sample to sample — the hidden cause of choppy calls and in-game rubber-banding.
Live jitter test
Takes a burst of latency samples and measures how much they vary — the standard deviation and the average swing between samples.
Idle — press “Run jitter test” to measure your latency stability.
What this test measures
Jitter is the variation in latency over time. Where the ping test tells you the average round-trip time, the jitter test tells you how consistent that round trip is. We collect a burst of samples, then report the standard deviation (the headline jitter figure), the average ping, and the spread between your fastest and slowest sample. Consistency is what keeps a voice call smooth and a game responsive — a connection with a low average but wild swings will still stutter.
How to read your result
| Jitter | Verdict | Impact |
|---|---|---|
| < 5 ms | Excellent | Rock-solid calls and gaming |
| 5–15 ms | Good | Fine for almost everything |
| 15–30 ms | Fair | Occasional glitches on calls |
| > 30 ms | Poor | Audio drops, stutter, rubber-banding |
If jitter is high, the usual culprits are Wi-Fi interference and bufferbloat — latency that explodes when the line is busy. Confirm the latter with the bufferbloat test, and check whether packets are being dropped entirely with the packet loss test.
Frequently asked questions
- What is jitter, in plain English?
- Jitter is how much your ping varies from one moment to the next. If your latency bounces between 20 ms and 120 ms, your jitter is high — even if the average looks fine. Stable latency matters more than a low average for calls and games.
- What is a good jitter value?
- Under 5 ms is excellent, under 15 ms is fine for most uses, and over 30 ms will cause audio glitches on calls and stutter in games. VoIP providers generally recommend keeping jitter below 30 ms.
- Why does my speed test look fine but my calls still break up?
- Because a speed test reports download speed, not stability. Choppy calls and rubber-banding are almost always caused by jitter, packet loss or latency spikes — the things a plain Mbps figure never shows.
- How can I reduce jitter?
- Switch from Wi-Fi to a wired connection, stop large background uploads/downloads, and check for bufferbloat. If jitter stays high while wired and idle, the cause is more likely upstream with your ISP or route.
Calls breaking up? Find the real cause
High jitter is a symptom, not a diagnosis. The Doctor runs ping, jitter, packet loss and latency under load together, then tells you whether it's your Wi-Fi, your router or your line — and how to stabilise it.