Two-Device Sync Test

Load this page on both devices, click Start Click Pattern, and the Two-Device Sync Test plays a repeating click alongside a visual metronome so you can judge by ear whether the two devices land together or drift apart. Drag the how out of sync did it sound slider to log what you heard — there's no way to measure sync between two separate devices directly from a browser, so your ears are the actual instrument here, which matters for multi-room setups and a phone paired to a TV. The positional audio, mic, and sidetone gives you a clear answer instead of guessing.

Whether you're pairing a camera with an external recorder or checking whether your Bluetooth headphones lag behind your TV, a Two-Device Sync Test tells you exactly how far apart your audio and video really are — in milliseconds, not guesswork. You'll watch a flash, listen for a beep, and drag a single offset slider until the two line up; what's left over is the exact delay you need to correct. This page covers what that number means, how to convert it into a fix your hardware understands, and where sync problems like this tend to hide — from streaming setups to home theaters.

Getting Started With the Two-Device Sync Test

Start by placing your two devices where they'll actually be used — one phone facing the screen or speaker, and a smartphone recording alongside a Bluetooth receiver. Press play, and you'll see a flash and hear a beep looping together at a steady BPM. Everything else on this page is about reading what happens next. Run the google meet speaker and microphone check to see exactly what's working and what isn't.

If you're testing by ear, just drag the offset slider until the flash and tone feel simultaneous. If you want frame-accurate proof before you trust the numbers for a broadcast or edit, record the screen with your camera in slow motion and let a microphone or auto-measure feature catch the acoustic delay directly.

What Your Beep Offset and Delay Numbers Mean

The number shown after calibration is the gap between when the reference flash fires and when the reference tone actually lands, shown in ms. A positive value means your audio arrived late; a negative one means it arrived early. That's the figure you'll program into your hardware to calibrate the two devices so they match.

Audio Delay Test Results: How to Read Your Sync Offset

Your result reflects two related numbers: the raw offset in ms, and — if you recorded on camera — the number of frames that offset spans at your recording's fps. Both describe the same gap; one is just easier to program into different hardware. Try the free test your teams audio for a quick, no-install way to check this yourself.

Converting Frame Rate Delay Into Milliseconds

The formula is simple: divide your frame offset by your capture rate, then multiply by 1000 to convert it to ms.

$$ \text{delay}_{ms} = \frac{\text{frames}}{fps} \times 1000 $$

At 24 fps, one frame off works out to about 41.7 ms; at 60 frames per second, that same one-frame error shrinks to roughly 16.7 ms — which is why exact timing matters as much as the number of frames you count.

Lip Sync Test Checklist for Streamers and Editors

Once you know your delay, the fix usually happens inside your editing or broadcast software, not on the calibration rig itself. In OBS, look for the audio delay field and enter your measured offset directly — positive to delay audio, negative to advance it. Think of this as running a quick sync offset test before you commit to a final mix.

If you're cutting the footage instead, most NLE software makes this just as simple. In Premiere Pro, drag the audio clip along the timeline until the waveform peaks line up with the visual flash; in Final Cut Pro or DaVinci Resolve, use the clip's timecode-lock feature to nudge it frame-by-frame. Export as WebM or your usual codec once the audio waveform matches.

Fixing Audio-Visual Drift in OBS, Premiere Pro, and Final Cut Pro

If you stream to Twitch or YouTube, viewers notice desync faster than almost anything else — even a couple of frames feels wrong once someone's talking on screen. Save your calibration clip so you have it on hand the next time you set up a new microphone or capture card.

Running a Bluetooth Latency Test for Headphones and Speakers

Bluetooth audio adds its own delay on top of anything already in your video pipeline, and it varies a lot by codec and device. If your Bluetooth headphones or a wired gaming headset sound like they're a beat behind the action, run the same test and read off the offset.

TWS Earbuds and Soundbar Delay

True wireless earbuds and other wireless headset designs are usually the worst offenders since the audio hops from your phone to the earbuds over its own short-range link, adding real, measurable audio latency before your ears ever hear it. A soundbar connected by optical audio or HDMI eARC tends to fare better, but it's still worth checking — especially during fast dialogue or a competitive match where sub-50ms accuracy actually matters.

AV Sync Tester Tips for Home Theater and Live Streaming

A smart TV or AV receiver is where most people first notice sync trouble, usually after switching inputs or updating firmware. Most have a Lip Sync or output delay setting buried in the audio menu — the number you found earlier is exactly what goes there.

Beep Offset

The gap between the reference flash and the reference tone, shown in ms after calibration.

Video Delay

Extra processing time added by a display, capture card, or broadcast pipeline before a frame reaches the screen.

Bluetooth Latency

The lag Bluetooth audio adds compared to a wired connection, which varies by codec and device.

Real-World Uses for Your Audio Video Sync Test Results

Gaming and Competitive Audio Latency Margins

In competitive play, audio cues often matter more than visuals — footsteps, gunshots, callouts — so even a small lag between what you see and what you hear can cost you a fraction of a second you don't have. Running this same test on your headset and monitor together tells you whether your setup is actually holding you back.

Video Editing and Post-Production Workflow

For video editing specifically, a head start on sync is worth more than any color grade — mis-timed dialogue is the fastest way to make an otherwise polished edit feel amateur. Keep your calibration numbers next to your project file, especially if you're bouncing between a sound mixing board, a dedicated video editor, and a switcher for multi-cam production.

A few practical notes: if the tool you're using has a frame-accurate radar visualizer, watch it settle into place rather than eyeballing the flash — it makes coarse adjustment easy at first and fine-tuning painless once you're close. If you need to test gear that can't run a browser page, most tools let you export a short clip to a USB stick or play it back from a media player instead, or played straight from YouTube if you don't want to deal with local files at all.

This kind of calibration isn't limited to home entertainment. Video production crews, audio engineering teams tuning a live mix, and podcasting setups checking a remote guest's feed all rely on the same flash-and-tone method. Everyday consumer electronics — smart speakers, wireless earbuds, even a budget soundbar — benefit from the same one-time check, well outside any specialized studio.