Free · 2-Minute Test
Bluetooth Audio Latency Test
Find out how much lag your Bluetooth headphones add, using a simple two-round reaction trick — no extra hardware needed.
Try It Now
Put your Bluetooth headphones on and make sure they're the active audio output, then start when you're ready.
How this test actually works
It's a two-part trick rather than a direct measurement, because a browser can't reach into your headphones and check their internal buffering. So instead, it measures your own reaction speed twice — once to something you see, once to something you hear through your Bluetooth headphones — and the difference between the two is a reasonable estimate of the extra delay your headphones are adding.
Round one flashes a box on screen and times how fast you tap after seeing it. Round two plays a short beep through your headphones and times how fast you tap after hearing it. Subtract the first number from the second, and what's left over is roughly your Bluetooth latency, since your own reflexes cancel out of the equation.
What counts as "good" latency
Under 60ms — you won't notice it at all, even for gaming or video calls.
60–150ms — fine for music and casual video watching, though fast-paced games might feel slightly off.
150–250ms — lip-sync starts to feel noticeably out during video, and it's distracting in competitive games.
250ms+ — clearly noticeable in everyday use. Worth checking your codec settings or trying a different pair.
Why Bluetooth adds delay in the first place
Every Bluetooth headphone has to encode audio on your device, send it over a radio link, then decode it again inside the earcup before you hear anything — and each of those steps takes a few milliseconds. The codec your headphones use matters a lot here. Plain SBC, the baseline codec every Bluetooth device supports, is usually the slowest. AAC is a bit better on Apple devices. aptX Low Latency, aptX Adaptive, and the newer LC3 codec were built specifically to shrink this gap, sometimes down under 40ms.
If your headphones support a "gaming mode" or "low latency mode," that's usually them switching to one of these faster codecs, trading a small amount of audio quality for a quicker connection.
A few quick questions
Why not just play a sound and time it directly?
Because there's no way for a webpage to know the exact moment sound physically reaches your ears — it can only know when it told the operating system to play something, and Bluetooth's delay happens after that point, outside the browser's view. Timing your own reaction to sight versus sound is the closest a browser can get without extra hardware.
My result came back near zero, or even negative. Is that normal?
It happens sometimes, especially if your headphones use a low-latency codec, or if you happened to react a touch faster in round two. We treat anything below zero as effectively "no noticeable delay" rather than a negative number, since human reaction time naturally varies a little between rounds.
Does this work with wired headphones too?
You can run it, but wired audio is essentially instant, so you're really just measuring the natural difference between your visual and audio reaction speed — which is a real, harmless thing, but not "latency" in the Bluetooth sense.
Is this as accurate as a lab measurement?
No, and it's not trying to be. Proper latency testing uses an oscilloscope and a physical audio-video loopback rig. This test trades that precision for something anyone can run in a browser in under two minutes — a solid ballpark figure, not a certified spec sheet number.