# Audio Delay Test For Bluetooth And Video Sync
This browser based audio delay test helps you inspect the gap between a visual cue and a sound on the device you are using now. It is useful for Bluetooth headphones, wireless speakers, wired headphones, room playback, and video sync checks. The tool generates a short click locally instead of asking you to download a test file.Start without microphone access
The manual pulse test works without a microphone. Watch the cyan visual marker and listen for the amber click, then move the alignment slider until they feel simultaneous. This produces a useful setup correction without pretending to identify a precise hardware latency.
# How To Test Bluetooth Audio Latency
- Select Bluetooth and set a comfortable listening level before starting.
- Run the pulse sequence from the same browser and device you use for playback.
- Compare the visual pulse with the click rather than judging a long piece of music.
- Move the alignment slider until the two cues meet, then note the signed correction.
- Repeat after changing codec, operating system, browser, volume mode, or distance.
| Mode | Best for | Main limitation |
|---|---|---|
| Speakers | Room playback and television speakers | Room distance and reflections affect the acoustic path. |
| Wired headphones | Direct headphone output | The microphone may not hear a closed headphone signal. |
| Bluetooth | Wireless headphones and speakers | Codec buffering can change between devices and apps. |
| Video sync | Display and player alignment | The player may add its own video frame and rendering delay. |
# Optional Microphone Measurement
When microphone access is available, the tool watches the local microphone analyser for each click and records the elapsed time from the scheduled audio event to the detected acoustic peak. The result uses the median of the samples because one reflection or operating system interruption should not dominate the estimate. The confidence badge also considers the spread between the tenth and ninetieth percentiles.Keep the microphone where you actually listen
For speakers, place the microphone at the listening position and keep the room quiet. For a video sync check, use the same speaker and display arrangement that produces the problem. Microphone processing and room reflections can be larger than the delay you are trying to compare.# Why Browser Audio Delay Results Vary
Audio delay is a path rather than a single permanent number. The browser schedules audio against an AudioContext clock, the operating system buffers it, the device may encode and decode it, and the speaker or headphone driver turns it into sound. A microphone adds its own capture and processing path. The test therefore describes the current browser, device, room, and settings instead of making a universal claim about a product.Do not treat this as a specification
Use the result to compare setups or troubleshoot an obvious sync problem. It does not replace a manufacturer specification, a calibrated measurement system, or a professional audio interface loopback test.