Jitter test
Measures how much your latency changes from one packet to the next. Steady latency keeps calls and games smooth even when the average ping is not especially low.
"Test under load" adds short download and upload bursts to show bufferbloat.
Latency trace
Teal is idle, amber is under load, red marks a packet with no reply.
Distribution
How often each round-trip time occurred.
The distribution appears after the first test.
Diagnostics from Chicago (US)
These tests run from our test node in Chicago (US), not from your browser. Use them to check whether a host is reachable and how far it is from a US Midwest network. Private and internal addresses can't be tested.
What jitter is
Jitter is the variation in delay between packets. If one packet takes 20 ms and the next takes 60 ms, audio and video apps have to buffer or drop data to keep playback smooth, which you hear as robotic voices or see as frozen video.
This test uses the RFC 3550 interarrival jitter estimator, the same method RTP-based voice and video software uses, so the number is comparable with what those apps report. The network echo test below reports a simpler mean variation over a few ICMP replies, so the two numbers are labelled differently.
What is a good jitter level?
Below 5 ms is very steady. Up to about 30 ms is the usual acceptable limit for voice calls, which is what most VoIP guidance recommends. Above 30 ms, expect choppy audio unless the app buffers heavily, and fast-paced games will feel inconsistent.
How to reduce jitter
- Switch from Wi-Fi to Ethernet, or move closer to the router.
- Pause uploads such as cloud backups, which often cause jitter on slower upload links.
- Enable SQM or Smart Queue in your router so busy traffic cannot crowd out calls.
- Check the latency trace on this page: regular spikes every few seconds often point to Wi-Fi scanning or a device on the network.
Questions
What is jitter testing?
A jitter test sends a stream of packets and measures how much the delay changes from one to the next. This one sends 40 packets and applies the RFC 3550 estimator.
Is 7 ms jitter bad?
No. 7 ms of jitter is fine for calls and games.
Is 35 ms jitter bad?
It is high for voice and video calls, which usually need under 30 ms. Try a cable connection and pause other traffic, then test again.
Why is my jitter high but ping low?
A low median with high jitter means most packets are fast but some are delayed, often by Wi-Fi interference, a busy upload, or a router that queues traffic.