Jitter Test: Measure How Stable Your Connection Is

Sample your latency many times over fifteen seconds and see how much it varies, how big the spikes get, and what that means for calls and games.

Your ping might average a respectable 30 milliseconds and still make a video call sound robotic or a game feel rubber-banded. The culprit is usually jitter: the variation in latency from one moment to the next. If one packet takes 25 ms and the next takes 90, apps have to wait, guess or drop data, and you hear and see the result. This jitter test samples your latency four times a second for up to thirty seconds and shows exactly how stable your connection is.

You get your jitter in milliseconds, the average latency, the standard deviation, the biggest spike above normal and any lost samples, plus a line chart that marks spikes in red. When the test ends, you get a plain verdict for gaming, voice and video calls and live streaming.

How to run the jitter test

1. Pause large downloads and streams on your network so they do not skew the result.
2. Choose a test length. Fifteen seconds is the default, thirty seconds catches more intermittent problems.
3. Press Start jitter test and leave the tab open while it samples.
4. Watch the latency line. A flat line is good. Red dots mark spikes well above your typical latency.
5. Read the verdict for each activity when the test finishes.

How jitter is measured

Consecutive differences

After a warm-up request, the test pings the server every 250 milliseconds and records each round trip time. Jitter is calculated as the average absolute difference between one sample and the next. This is the same idea used by the RTP standard that carries most voice and video calls, which makes the result directly relevant to call quality.

Standard deviation

Standard deviation measures how widely all samples spread around the average, regardless of order. Jitter focuses on sudden changes between neighbours. Looking at both tells you whether the connection wobbles constantly or is steady with occasional bursts.

Biggest spike

This shows how far the worst sample rose above your median latency. A single big spike can freeze a game for a moment even when overall jitter looks fine.

Lost samples

Any sample that fails or takes longer than two seconds is counted as lost. Loss above about 1 percent is enough to cause audible glitches on calls.

Reading the latency chart

The teal line plots every sample in order, and the dashed purple line marks your median latency. A healthy connection draws a nearly flat line hugging the median, with small ripples of a few milliseconds. A saw-tooth pattern that jumps up and down on almost every sample means constant instability, typical of weak Wi-Fi. A mostly flat line with tall isolated peaks means something intermittent is interrupting traffic, such as another device starting an upload or a phone joining the network. A line that slowly climbs and stays high often means a large transfer began partway through the test.

When to run the test

Run it at the times you actually play or take calls, not just when the house is quiet. Evening results tell you more about a gaming session than a morning test does. If you are troubleshooting, test once on Wi-Fi and once on a cable in the same spot, a minute apart. The difference between the two runs shows how much of the problem is your wireless link and how much comes from your provider.

What is a good jitter?

Calls use a jitter buffer that briefly holds incoming audio to smooth out variation. Small jitter is absorbed invisibly. Large jitter forces the buffer to grow, which adds delay, or to drop packets, which causes gaps.

Common causes of high jitter

• Wi-Fi interference. Neighbouring networks, microwaves, walls and distance all make wireless timing irregular.
• Bufferbloat. When someone uploads or downloads heavily, packets queue in the router and latency swings wildly.
• Congested networks. Busy evenings on shared connections often show higher jitter.
• Mobile and satellite links. Signal changes and handovers make latency less predictable.
• Power saving on network adapters, which can delay packets while the adapter wakes.

How to reduce jitter

Go wired

Ethernet is the single most effective fix. It removes wireless interference completely and usually brings jitter down to a few milliseconds.

Tame your uploads

Pause cloud backups during calls and games, or enable smart queue management (often called SQM or QoS) on your router, which keeps latency stable when the line is busy.

Improve Wi-Fi

Use the 5 GHz or 6 GHz band close to the router, move the router off the floor and away from walls, and consider a mesh system in larger homes.

Jitter, ping and speed together

These three numbers describe different things. The ping test shows how long a round trip takes. Jitter shows how steady that time is. The internet speed test shows how much data can flow. For calls and streaming, make sure your microphone and webcam are ready too, since a stable connection only helps if the input is clean. Gamers can pair a steady line with sharp reflexes in the reaction time test.

Frequently asked questions

Related tools