Fix OBS Media Source Video Lagging Behind Audio

If you are experiencing issues in OBS Studio where a media source’s video trails behind its accompanying audio, you are dealing with a common playback synchronization problem. This article provides a straightforward, step-by-step guide to resolving this lag, covering solutions ranging from adjusting internal audio delays to optimizing OBS hardware settings and file formats.

1. Adjust the Audio Sync Offset

If the video lag is consistent throughout the playback, the quickest workaround is to delay the audio so it matches the lagging video.

  1. Locate the Audio Mixer dock in OBS Studio.
  2. Click the three dots (gear icon) next to your Media Source or your main audio output and select Advanced Audio Properties.
  3. Find your media source in the list.
  4. Locate the Sync Offset (ms) column.
  5. Enter a positive value in milliseconds to delay the audio (e.g., 200 for a 0.2-second delay) or a negative value if you need to advance it.
  6. Test the playback and adjust the millisecond value until the audio and video are perfectly aligned.

2. Toggle Hardware Decoding

If your computer’s CPU is struggling to decode the video, the video frames will drop, causing the video to fall behind the audio. Enabling hardware decoding offloads this work to your GPU.

  1. Double-click your media source in the Sources dock to open its properties.
  2. Scroll down and check the box for Use hardware decoding when available.
  3. Click OK.
  4. If the option was already checked and you are still experiencing lag, try unchecking it, as certain video codecs perform better with CPU decoding depending on your hardware configuration.

3. Change Media Source Performance Settings

Certain properties within the Media Source can cause playback hiccups, especially on longer streams.

  1. Double-click the problematic media source to open Properties.
  2. Uncheck Close file when inactive. Keeping the file loaded in the background prevents lag when the source is transitioned onto the screen.
  3. Check the box for Limit speed when invisible if you want to save resources when the video is not actively being shown.

4. Run OBS Studio as Administrator

When Windows runs out of GPU resources, it prioritizes gameplay or other applications over OBS Studio, resulting in dropped video frames. Running OBS as an administrator forces Windows to allocate sufficient GPU resources to the software.

  1. Close OBS Studio completely.
  2. Right-click the OBS Studio shortcut on your desktop or start menu.
  3. Select Run as administrator.

5. Re-encode the Media File

If the desync persists, the video file itself may have a variable framerate (VFR) or use a high-bitrate codec that OBS struggles to decode in real-time.