Jitter test. How even is the ping?
Jitter is how much the delay changes from one packet to the next. A call or a game can live with a steady 60 ms; it stutters on a ping that swings between 20 and 120. This test sends twenty round trips to this site, reports jitter as RFC 3550 defines it, and measures how the latency moves while the line is loaded.
One check
- Internet
One check after another, with your progress along the top and a plain verdict on each. Nothing you show the camera or say into the microphone leaves this page.
In short
Jitter test: the answer first
A jitter test measures how much the delay changes from one packet to the next. This one sends twenty round trips to this site, reports jitter the RFC 3550 way, as the mean change between consecutive round trips, with the spread beside it, and repeats the round trips while the line is loaded.
Reading your result
- Jitter and spread answer different questions
- Jitter catches a ping that jumps from packet to packet; spread catches one that drifts. A call suffers most from the first.
- Compare idle with loaded
- Jitter that appears only while the line downloads or uploads is bufferbloat, and the fix is on the router.
- Against the line
- Our warn line is 50 ms; voice planning guides commonly use 30 ms. On a cable, single digits are common.
What it measures
Measured here, not assumed.
- Round trips
- Twenty small round trips to this site, the first two dropped as the connection opens. The median is the latency.
- Jitter
- The mean of the absolute differences between consecutive round trips: the quantity RFC 3550, the standard for real-time media, builds its jitter estimator from.
- Spread
- The standard deviation of the round trips, shown beside jitter. Spread catches a ping that drifts slowly; jitter catches one that jumps from packet to packet.
- Under load
- Round trips every 200 ms while the line downloads and uploads, so jitter that appears only when the line is busy is not missed. The increase is graded on Waveform's bufferbloat bands.
- Against a line
- Our warn line for jitter is 50 ms. VoIP planning guides commonly put the limit for voice at 30 ms; video calls tolerate a little more.
If it fails
The usual failures, and what fixes each.
- Jitter is high on Wi-Fi
- Run once with a cable. If jitter drops, the wireless link is the cause: move closer to the router, use the 5 GHz band, or keep the device on a cable for calls and games.
- Jitter rises only under load
- That is bufferbloat. Turn on Smart Queue Management (QoS with fq_codel or CAKE) on the router, and pause uploads and backups.
- Jitter is high on every connection
- Turn off any VPN and run again. If it stays high on a cable with nothing else running, the provider's line is the cause; run the test at another time of day before you call them.
Where a browser stops
What it cannot tell you.
- Jitter on the path to a game server or a call service elsewhere. The round trips go to this site.
- Which direction the jitter is in. A browser times round trips, so upstream and downstream jitter are not separated.
- Packet loss, which needs a relay server we do not run; it is reported as not measured.
- ICMP ping, which browsers cannot send. The round trips are small requests to this site.
Privacy
Nothing leaves this page.
The camera and microphone are read on this page and stopped as soon as they have been measured. The clip you can play back lives in the browser's memory and is discarded when you leave. The location check discards the position. The internet test sends random bytes to this site and nothing else. The result is stored nowhere unless you ask for it by email, and then only the fact that an email was sent is kept.
Questions
Jitter test, answered
- What is jitter in internet speed?
- The variation in delay between packets. A low average ping can hide large swings, and the swings are what freeze video and make games rubber-band. This test reports it the way RFC 3550 does, as the average change from one round trip to the next.
- What is a good jitter for gaming and calls?
- As low as you can get it. Our warn line is 50 ms; VoIP planning guides commonly put the limit for voice at 30 ms. Single-digit jitter on a cable is common.
- What is the difference between jitter and ping?
- Ping, or latency, is how long a round trip takes. Jitter is how much that time changes from one round trip to the next. A line can have a high ping and low jitter, which feels laggy but steady, or the reverse.
- Why is my jitter high on Wi-Fi?
- Wi-Fi shares the air with other networks and devices, and retries what is lost, so some packets wait longer than others. A cable removes that; the 5 GHz band and a closer router reduce it.
- Can jitter be fixed without changing provider?
- Often. A cable instead of Wi-Fi, the 5 GHz band, no VPN and Smart Queue Management on the router remove most jitter that starts in the home.
Read next