Turn the volume up and press start — a short click will play after a brief pause.
A marker will sweep across this timeline while the click plays. Tap the spot where you heard it.
01000
Timeline length
Headphones delay test
Find out how much delay your headphones add. Play a click, mark the moment you heard it on the timeline, and repeat a few times for a reliable figure — no apps, no downloads, no microphone.
This test measures the delay you actually perceive. Your browser plays a short click and, at exactly the same instant, starts a marker moving across a timeline. You mark the point where you heard the click, and the distance from the start is your latency. Taking several measurements and reading the median cancels out most of the guesswork in any single judgement.
It is a quick way to find out whether your Bluetooth headphones are the reason video looks out of sync or a game feels sluggish, and to compare one pair against another. Because you are judging a sound against what is on screen, the result also carries your display’s own latency, so read it as perceived delay rather than a lab measurement. Everything runs in your browser, and nothing is recorded or uploaded.
Frequently asked questions
Your browser schedules a short 1 kHz click and starts a marker sweeping across the timeline at the same instant. You mark the point where you heard the click, and the distance from the start is your delay. Repeating it and taking the median cancels out most of the guesswork.
Expect roughly ±30–80 ms on a single mark, mostly from the difficulty of matching a sound to a moving marker. The median of five or more marks is far tighter. The figure also includes your screen's own latency, so read it as the delay you perceive rather than the headphone figure alone.
Bluetooth audio is compressed, buffered, transmitted and decoded before it reaches the drivers, and every stage adds time. 150–300 ms is normal for the SBC and AAC codecs, which is why lip sync drifts when you watch video.
aptX Low Latency and aptX Adaptive are typically around 40–80 ms, and LC3 with Bluetooth LE Audio is similar. Standard aptX lands near 100 ms, while AAC and SBC are commonly 150–300 ms. Both your device and your headphones have to support the same codec for it to be used.
Analogue wired headphones on a 3.5 mm jack are effectively instant — the only delay is your device's own audio buffer, usually 5–30 ms. USB-C headphones with a built-in DAC add a little more.
Use wired headphones for anything timing-critical. On Bluetooth, pair a device and headphones that share a low-latency codec, stay close to the source, reduce interference from other 2.4 GHz devices, and switch on any game or low-latency mode your headphones offer.
Some of the variation is you rather than your hardware, because matching a sound to a moving marker is imprecise. Bluetooth also re-buffers dynamically, so the real delay drifts with signal quality. Take several measurements and read the median together with its spread.