Few things ruin a professional stream or recording faster than a "lip-sync" issue. If your microphone audio hits the viewer’s ears before (or after) they see your mouth move, it creates a jarring experience. This happens because video processing (especially with high-res webcams or capture cards) takes significantly longer than audio processing.
In this guide, we will use the OBS Sync Offset feature to perfectly align your voice with your video frames.
Table of Contents
The "Clap Test": How to Measure Your Delay
Before you change settings, you need to know exactly how many milliseconds (ms) you are off. Don't guess—measure it.
- Start a local recording in OBS.
- Look directly at the camera and clap your hands loudly.
- Open the recorded file in a video editor (like DaVinci Resolve or CapCut) or even VLC.
- Find the frame where your hands touch. Now, look at the audio waveform and see how many frames/milliseconds apart the "peak" is from that frame.
Pro Tip: At 60 FPS, each frame is approximately 16.7ms. If your audio is 3 frames early, you need a 50ms delay.
Method 1: Using Advanced Audio Properties
This is the primary way to delay your microphone so the video has time to "catch up."
- Locate the Audio Mixer dock in OBS.
- Click the Three Dots (or Gear icon) next to your Mic/Aux source.
- Select Advanced Audio Properties.
- Locate the Sync Offset (ms) column for your microphone.
- Enter a positive value (e.g.,
200) to delay the audio.
Note: Most USB webcams require an offset between 150ms and 300ms.
Method 2: Using Render Delay (When Video is Too Slow)
If your audio is actually slower than your video (rare, but happens with complex audio routing), you must delay the video instead.
- Right-click your Video Capture Device in the Sources list.
- Select Filters.
- Click the + icon and choose Video Delay (Async).
- Enter the delay in milliseconds. (Warning: This consumes more RAM as OBS must buffer video frames).
The Drift Fix: Matching Sample Rates
Does your audio start in sync but slowly drift out of sync over an hour? This is usually a Sample Rate Mismatch.
- Check Windows: Right-click the Speaker icon > Sound Settings > More Sound Settings > Recording Tab > Properties > Advanced. Ensure it is set to 48000 Hz (DVD Quality).
- Check OBS: Go to Settings > Audio. Ensure the Sample Rate is also set to 48kHz.
If one is 44.1kHz and the other is 48kHz, your audio will "drift" over time.
Quick Reference: Common Sync Offset Values
While every setup is different, these are the industry-standard starting points for 2025 hardware:
| Device Type | Suggested Offset (ms) |
|---|---|
| USB Microphone + 1080p Webcam | 150ms to 250ms |
| XLR Mic + 4K DSLR (Capture Card) | 200ms to 400ms |
| NDI / Wireless Camera Sources | 500ms+ |
| Desktop Gameplay (Internal) | 0ms (Usually native) |
Frequently Asked Questions
A: By default, no. Sync offset only affects the recorded/streamed output. If you want to hear the delay (which can be confusing), you must change "Audio Monitoring" to "Monitor and Output" in Advanced Audio Properties.
A: Yes, OBS supports negative values (e.g., -100), but this only works if there is already a delay in the system. You cannot "predict" audio before it happens, so negative offsets are rarely the solution for mic lag.
A: This is often caused by "Use Device Timestamps." Go to your Mic's Properties in OBS and try unchecking "Use Device Timestamps." This forces OBS to manage the timing manually, which is often more stable.
For further technical help, refer to the OBS Project Wiki or join the OBS Discord community.