Audio/video sync test
Is the sound late on your Bluetooth headphones, TV or soundbar? Watch the flash, listen to the beep, and move the slider until they happen together.
How to use it
- Connect the headphones or speaker you want to check and press Start. Use a moderate volume.
- If the beep comes after the flash, move the slider right; if before, move it left. Small steps help at the end.
- The page also shows the delay your browser reports; the slider adds what the browser doesn't know — typical for Bluetooth.
What the numbers mean
- Under ~60 ms: nobody notices. 60–150 ms: fine for films, noticeable in games and rhythm apps. Over 150 ms: lips and speech visibly drift apart.
- Typical Bluetooth headphones add 150–250 ms; low-latency codecs (aptX LL/Adaptive, LC3) and gaming modes reduce it a lot.
- Many TVs, soundbars and apps have an "audio delay / AV sync" setting: enter the number you found here.
Frequently asked questions
Why does a video look fine but games feel late?
Video apps can delay the picture to match the sound; games can't, because they must react immediately.