What is Sync Offset in OBS Studio?

This article explains the “Sync Offset” setting in OBS Studio’s Advanced Audio Properties, detailing how it functions, why it is crucial for resolving audio-to-video desynchronization (lip-sync issues), and how to apply the correct values to achieve perfect stream alignment.

The “Sync Offset” setting in OBS Studio is a calibration tool used to adjust the timing of an audio source relative to your video feed. Because audio and video signals are processed by different hardware and software pipelines, they often arrive in OBS at different times. This discrepancy causes distracting lip-sync issues where a speaker’s voice does not match their mouth movements. Sync Offset solves this by allowing you to shift the audio timing, measured in milliseconds (ms), to bring both feeds into perfect alignment.

To access this setting, click the three dots (or gear icon) next to any audio source in the OBS Audio Mixer, select “Advanced Audio Properties,” and locate the “Sync Offset (ms)” column next to your desired audio input.

• Positive Sync Offset: If your audio is heard before the corresponding action is seen on screen, you need to delay the audio. Entering a positive value (e.g., 200 ms) will delay that specific audio source by that duration.
• Negative Sync Offset: If your audio is heard after the action is seen on screen, you need the audio to play sooner. Entering a negative value (e.g., -200 ms) tells OBS to delay the video capture device to let the audio catch up.

To determine the correct offset value, record a short test clip of yourself clapping. Import the recording into a video editor to measure the exact millisecond gap between the audio spike of the clap and the visual frame where your hands meet, then enter that exact number into the Sync Offset field.