Audio Latency Test
Find out how late your Bluetooth headphones, earbuds or speakers play sound. Tap along to a beat, let your microphone hear the speaker in a loopback test, or slide a flash until it lines up with the click. Compare against a wired baseline to get the extra delay in milliseconds.
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Browser-reported values appear after the first test starts. Bluetooth delay is often not reported, so measure it below.
A click plays at a steady beat. Tap Space, click or touch the pad exactly when you hear each click. Don't look at the screen for timing; listen. 4 count-in beats, then 16 taps are measured.
Place the earbud, headphone cup or speaker right next to your computer or phone microphone, set the volume to about 60%, and keep the room quiet. Six short chirps are played and recorded; nothing leaves your device.
The recording and detected chirps will appear here.
A click plays once per second together with a flash. If the sound arrives late, the flash seems early. Move the slider until flash and click feel simultaneous. The value is your audio delay, ready to enter in a video player's or TV's audio sync setting.
How to use the Audio Latency Test
- Connect the device you want to test (Bluetooth headphones, earbuds or speaker) and set a comfortable volume.
- Tap test: press Start tap test and tap Space, click or touch the pad exactly when you hear each click. After the count-in, 16 taps are measured.
- Mic loopback: hold the earbud or speaker close to your microphone, press Start loopback test and allow microphone access. Six chirps are played and timed.
- Save a baseline: run the same test with wired headphones or the built-in speaker and press Save as baseline. Then test the Bluetooth device to see the difference.
- Sync slider: move the slider until the flash and the click feel simultaneous; the slider value is the audio delay to compensate in apps or games.
Three ways to measure audio delay
| Method | What it measures | Best for |
|---|---|---|
| Tap test | Time from the click being sent to the audio system until your tap, which is audio delay plus your personal timing offset | Any device, no microphone needed; compare against a wired baseline |
| Mic loopback | Round trip: speaker output, sound traveling through the air and microphone input, found by cross-correlating six chirps | The most objective result; compare Bluetooth against wired to isolate the output delay |
| Sync slider | How much a flash must be delayed to look simultaneous with the click, which is audio delay minus display delay | Finding the value to enter in a TV, video player or game's audio offset setting |
How to get the extra Bluetooth latency
The browser cannot see when sound actually leaves a wireless earbud, so the reliable way is a comparison. Run the tap test or loopback test with wired headphones or the built-in speaker and press Save as baseline. Switch output to the Bluetooth device and run the same test again. Everything that both runs share, including your tapping habit, the computer's audio buffer and the microphone delay, cancels out:
extra Bluetooth delay = result with Bluetooth − baseline result
For the loopback test the air gap adds about 2.9 ms per meter (sound travels roughly 343 meters per second), so keep the speaker or earbud at the same short distance from the microphone in both runs.
Tips for reliable results
- Use the same browser and tab for the baseline and the comparison, and close apps that play audio.
- In the tap test, listen with your eyes closed or looking away; tapping on a visual cue measures your eyes, not the audio.
- Repeat each test two or three times; the median of the runs is more reliable than a single run.
- Earbuds may switch codec or enter a gaming mode with different latency; test each mode you use.
- Phones and laptops in battery saver mode may use larger audio buffers, which raise latency.
Frequently asked questions
How accurate is the tap test?
Your result equals the audio delay plus your personal timing habit. Most people tap slightly ahead of a steady beat, and touch screens add their own delay. That is why the test works best as a comparison: save a baseline with wired headphones or the built-in speaker, then test the Bluetooth device the same way. The difference between the two medians is the extra latency, usually accurate to within about 10 to 20 ms.
What does the microphone loopback test measure?
It plays short chirps and records them with your microphone, then finds each chirp by cross-correlation. The time between scheduling the chirp and hearing it is the round-trip latency: audio output, the air gap and audio input together. With a wired baseline saved, the difference between the two round trips is the extra output delay of the Bluetooth device, because the microphone side stays the same.
What is a normal Bluetooth audio latency?
It depends on the codec and the device. Classic Bluetooth audio with the SBC or AAC codec commonly adds roughly 100 to 300 ms. Low-latency codecs and gaming modes, such as aptX Low Latency, which is specified at around 40 ms, or the gaming modes of many earbuds, bring it down considerably. Wired headphones add almost nothing beyond the computer's own audio buffering.
Why does the loopback test say no clear signal was found?
The microphone did not hear the chirps clearly above the background noise. Raise the volume, hold the earbud or speaker within a few centimeters of the microphone, keep the room quiet, and make sure the right microphone is selected in your browser. Some headsets switch to a low-quality call mode when their own microphone is used, so use the computer's microphone instead.
Why is the browser-reported output latency different from my result?
Browsers report the latency they know about, such as the audio buffer and the system mixer. Many operating systems do not report the extra delay of Bluetooth devices to the browser, so the reported value often stays low even with Bluetooth. Measured results from the tap or loopback test include the full delay.
How can I reduce Bluetooth audio delay?
Use a gaming or low-latency mode on the earbuds if they have one, choose devices and phones that support low-latency codecs, keep the device close with no obstacles, and update its firmware. For video, most players and TVs have an audio delay or AV sync setting; enter the value from the sync slider there. For music production or rhythm games, use wired headphones.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.