SYNC CHECK

AV Sync Reference Loop

Use this to check lip sync through a real screen, camera, and microphone chain. It gives you a repeatable visual hit and audio hit so you can compare what the path is actually doing.

Subjective reference tool only. It helps you compare early vs late sync. It does not measure exact chain latency or calibrate a system.

Controls

Set the offset you want to compare, pick the reference blip that reads best through your chain, then switch to presentation mode and film the loop.

0 ms

`0 ms` means the beep lands with the center hit. Positive values mean audio after picture. Negative values mean audio before picture.

Quick comparison presets
Wider threshold references for subjective checks

Slower loops are often easier to judge through cameras, return feeds, and delayed program outputs.

Lower tones are easier to live with for longer checks. Higher tones and the click can cut through room noise, small speakers, or compressed paths more clearly.

Display / Browser Info

Viewport -
Screen -
Device Pixel Ratio -

Browser/display information only. Useful for notes and repeatability, not for physical screen calibration.

Practical sync reference Built to be easy to film

The sync moment is the center hit. Watch when the sweep bar crosses the middle target, compare that visual moment against the beep, and judge whether your chain feels aligned, early, or late.

0 ms hit point
Audio cue is aligned with the visual hit.
Presentation mode switches to a loop-only fullscreen view with a minimal exit control, so the pattern can fill the display without the normal tool UI around it.

How to use it

  • Put this page on the display your camera sees.
  • Leave a microphone open so the short blip travels through the same real path.
  • Judge sync on the recording, stream return, switcher output, or monitor that actually matters.
  • Compare against the presets if you need a known early/late reference instead of guessing.

Reference notes

Audio Latency Calculator Use this when you already know the buffer or offset path and need the number in milliseconds. Fix lip sync in your stream Start here if the job is a fast stream-side sync fix under pressure. Fix OBS audio sync Use the OBS-specific path when the problem lives inside the OBS chain.