A/V Sync Tester
Calibrate your audio-visual equipment latency with frame-level precision.
Speed: 60 BPM
How to use:
1. Turn up your volume. Start the test.
2. Use your smartphone to record a video of this screen (use 60fps or Slow Motion mode for best results).
3. Playback the video frame-by-frame.
4. Find the exact frame where you hear the Beep. Check the position of the scanner line. If it's past the center (0ms) into the positive numbers, your audio is late.
Compress & Convert Your Video
Need to prepare your video for delivery?Medrea offers professional, hardware-accelerated compression and transcoding tools for macOS.
Download Medrea for MacOnline Audio Video Sync Test
A professional-grade, frame-accurate tool to measure audio latency and video delay. Whether you are a video editor synchronizing sound in post-production, a gamer calibrating a home theater system, or a developer testing Bluetooth latency, this tool provides the physical reference point you need.
Reference Flash & Beep
Uses a high-contrast visual flash synchronized perfectly with a 1kHz sine wave beep. By recording this output with a high-speed camera (e.g., iPhone Slow Motion), you can count the frames between the visual event and the audio event to determine exact millisecond delay.
Check Bluetooth Latency
Wondering why your AirPods / Bluetooth headphones feel laggy? Run this test to visually see the delay. Typical Bluetooth latency is between 100ms - 300ms, which will show up clearly on our radar visualizer.
Home Theater Calibration
Use this pattern to adjust the "Audio Delay" or "Lip Sync" settings on your TV or AV Receiver. Adjust your equipment settings until the beep sounds exactly when the radar hits the 12 o'clock mark.
Variable Speed (BPM)
Adjust the loop speed from 30 to 120 BPM. Slower speeds help with initial coarse adjustment, while faster speeds (like 60 or 120 BPM) mimic standard video frame rates for fine-tuning.