Drag right if the click comes after the hit, left if it comes before. Stop when they feel like one event.
Under 20 ms is indistinguishable from perfect. Nothing to change.
Getting this page onto your TV
- • TV browser: most smart TVs have one - type tonal.fm/av-sync-test.
- • HDMI from a laptop: the most faithful route; the laptop’s own audio goes out over HDMI too.
- • AirPlay / Chromecast: mirror a phone or laptop. Adds its own delay to both picture and sound equally, so the offset you read is still your TV/sound path.
- • Route audio the way you actually watch: TV speakers, ARC/optical to a soundbar, receiver, Bluetooth.
Reading the number
- • Positive (sound late): normal for soundbars, receivers, Bluetooth. Reduce audio delay, or speed up the picture with game / PC mode.
- • Negative (sound early): picture processing is the bottleneck. Add that many ms of audio delay.
- • Tolerance: ~45 ms early or ~125 ms late passes unnoticed for most viewers (ITU-R BT.1359). Aim for under ±40.
- • Re-test per input: apps, consoles and set-top boxes take different paths.
Where the lip-sync setting lives
| Samsung TV | Settings → Sound → Expert Settings → Digital Output Audio Delay |
| LG TV | Settings → Sound → Advanced / AV Sync Adjustment |
| Sony Bravia | Settings → Display & Sound → Audio output → A/V sync |
| Apple TV | Settings → Video and Audio → Wireless Audio Sync (runs its own calibration with an iPhone) |
| Sonos | App → System → (your TV room) → TV Dialog Sync |
| Denon / Marantz | Setup → Audio → Audio Delay (Lip Sync) |
| Yamaha | Setup → Sound → Lipsync (manual or Auto via HDMI) |
| Roku | Settings → Audio → Audio leveling / or set delay on the TV instead |
Menu names drift between firmware versions; search the manual for “lip sync”, “AV sync” or “audio delay”. Measuring headphones rather than a TV? Use the audio latency test or the Bluetooth latency test.
AV Sync FAQ
How do I test lip sync on my TV?
Put this page on the screen you are judging - open it in the TV’s browser, or mirror a laptop or phone through HDMI, AirPlay or Chromecast - and send the sound through the path you normally use (TV speakers, soundbar, receiver, Bluetooth). Press Start: a ball drops onto a line once a second and a click plays at the moment of impact. Drag the slider until the click and the impact feel simultaneous. The slider then shows the offset between your picture and your sound.
What does “audio lags video” mean and how do I fix it?
The sound arrives after the picture - the usual case with soundbars, Bluetooth speakers and receivers, which add processing and buffering. Fix it by delaying the video or, more commonly, by reducing the audio delay: most soundbars and receivers have a “lip sync” or “audio delay” setting, and some TVs let you set a negative delay on the digital output. If the only control available is an audio delay, set it to zero and turn on your TV’s game or PC mode to speed up the picture instead.
What does “audio leads video” mean?
The sound arrives before the picture. This happens when the TV’s picture processing (motion smoothing, upscaling, HDR tone-mapping) takes longer than the audio path - common when audio goes straight to a receiver while the TV processes the video. The fix is an audio delay equal to the reading: every receiver, soundbar and most TVs have one, labelled Lip Sync, AV Sync or Audio Delay.
How much AV sync error is noticeable?
Broadcast standards allow roughly 45 ms of audio lead and 125 ms of audio lag before most viewers notice (ITU-R BT.1359). Lag is tolerated more than lead because in the real world sound always arrives after light. Aim for an offset under ±40 ms; under ±20 ms is indistinguishable from perfect.
Why is my soundbar out of sync only on some inputs?
Each source takes a different video path. Apps built into the TV are processed once; an external box over HDMI may be processed twice; a games console in game mode skips most processing. Run this test from the source that bothers you, and set the delay on the soundbar per input if it allows it - otherwise pick a compromise value or use the TV’s per-input picture modes.
Can Bluetooth speakers be used for TV audio without lip-sync problems?
Only if something compensates. Bluetooth adds 100-250 ms on typical speakers, and most TVs do not delay the picture to match. Some TVs (Samsung, LG) do compensate for paired Bluetooth headphones specifically. Measure here; if the reading is over about 80 ms and you have no delay setting that goes far enough, a wired, optical or HDMI ARC connection is the real fix.