Photosensitivity warning: This test uses screen flashes. If you have photosensitive epilepsy, please do not use this tool.
Audio Sync Checker - Audio Delay Test - Bluetooth Latency Test
A free online tool to measure audio sync issues (audio delay) with Bluetooth earbuds, headphones, monitors, and capture cards right in your browser. Features an A/V sync mode that plays a screen flash and beep simultaneously, and a tap measurement mode that calculates delay in milliseconds. Use it to check wireless earphone latency, lip sync, and gaming monitor audio delay.
Audio Sync Checker
Check and measure audio sync issues (audio delay) with Bluetooth earphones or monitors.
Watch your volume. A beep tone will play. Please check your system volume before starting.
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A/V Sync Check
A screen flash and beep will play simultaneously. If you hear the sound delayed, there is audio latency.
This area will flash
Interval1500 ms
With a wired connection, the flash and beep should feel nearly simultaneous. If you hear the sound delayed over a Bluetooth connection, audio latency is present.
Frequently Asked Questions (FAQ)
Q. Why does audio delay occur with Bluetooth?
A. Bluetooth requires encoding and decoding audio data for wireless transmission, and this processing time causes the delay. The amount of latency varies depending on the codec used (SBC, AAC, aptX, LDAC, etc.).
Q. How do I use the A/V Sync Check?
A. Press "Start Playback" and the screen will flash while a beep plays simultaneously and repeatedly. If the flash and sound feel simultaneous, there is no delay. If the sound seems delayed, audio latency is present. You can adjust the playback tempo with the interval slider.
Q. How can I reduce audio delay?
A. Use earphones that support low-latency codecs (aptX, aptX Low Latency, aptX Adaptive), use the audio delay compensation feature in your video player, or switch to a wired connection.
Q. What if audio delay is an issue in games?
A. For games like FPS where audio delay is critical, a wired connection is recommended. Some Bluetooth earphones with a "game mode" feature can reduce latency to around 40-60ms.
This tool is intended for simple delay measurement in the browser. Results may differ from measurements taken with dedicated equipment due to browser and OS processing overhead.