RunTheTests
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Echo / Loopback Test

Find out whether the person you are calling can hear themselves through you.

Volume warning

This test plays tones that can be loud and may damage hearing or speakers. Turn your volume down before starting, then raise it gradually.

How this test works

A short tone plays through your speakers twice while the microphone listens: once with the browser's echo cancellation switched off, and once with it on. The pair of answers is what makes the result meaningful, and the reading is the opposite of the intuitive one. Hearing your own speakers in your own microphone is not the fault — it is the normal state of every laptop ever made, and precisely what echo cancellation exists to remove. The fault is hearing the tone through the cancellation, because that is what the person on the other end hears as an echo of their own voice. Hearing nothing either way is the best outcome and the most common on a headset: no echo path exists at all. Before the tone plays, the level at its frequency is measured so a room with a whine at the same pitch is not mistaken for an echo, and detection requires the tone to sit twelve decibels above that background.

What the results mean

Echo cancellation working
The microphone heard the speakers with cancellation off and heard nothing with it on. An echo path exists, as it does on any laptop, and the browser is removing it before anyone else hears it. This is the result you want on speakers.
Echo leaking
The tone was audible even with cancellation on. This is the fault worth fixing, and it is invisible to you — only the other end experiences it, as a delayed repeat of their own voice.
No echo path
The microphone did not hear the speakers either way. Nothing to cancel and nothing to fix, which is the normal result on headphones or with the microphone away from the speakers.
Round-trip delay
How long the tone took to travel from speaker through the air to microphone. Measured at frame resolution, so it is good to about 20 milliseconds and is not a precise figure.

Common problems and fixes

People say they hear themselves when talking to you
That is exactly the leaking case. Turn the speaker volume down first — echo cancellation has a level it can cope with and loud speakers close to a microphone exceed it. This alone resolves most cases and costs nothing.
The test says no echo path but callers still complain
Run it again on the output you actually use for calls. Testing on headphones will always report no path, which says nothing about the laptop speakers a call goes through.
The browser refused to disable cancellation
Safari and several mobile browsers force it on permanently. Chrome or Edge on desktop will run the full comparison. There is no way for a page to override it.
The result changes between runs
Echo cancellation adapts over the first few seconds of audio, so the very start of a call behaves differently from the middle. Run it two or three times and treat a repeated leak as the finding rather than a single one.

Frequently asked questions

Why is hearing my speakers in my microphone not the problem?

Because it is unavoidable on any device where the two are in the same room, which is every laptop and every desktop with speakers. Echo cancellation was invented precisely for that arrangement, and it works well. Flagging the raw path as a fault would tell most visitors something is wrong when their setup is behaving normally.

Why can I not hear the echo myself?

Because the echo is in what you send, not in what you receive. Your microphone picks up your speakers and sends it back, so the other person hears their own voice returning. Everything sounds fine at your end, which is why this fault survives so long and needs a test rather than a listen.

Does this test my call software's echo cancellation?

No. It tests the browser's, on this machine. Most call applications apply their own, sometimes better and sometimes worse, so a clean result here is good evidence that the physical setup is manageable rather than a guarantee about a specific app.

Should I just use headphones?

It is the reliable answer, and it is why call centres do it. Headphones remove the echo path entirely instead of relying on software to subtract it, which means nothing has to adapt, nothing can be overwhelmed by volume, and no processing sits between you and the person listening.

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