Audio Is Out of Sync With Video

Why Audio Gets Out of Sync

Type 1: Constant Offset (Always Ahead or Always Behind)

The audio is consistently X milliseconds off throughout the entire video. This is the easiest to fix.

Common causes:

• Screen recording software that adds a fixed delay to one stream
• Converting between formats with incorrect timestamp mapping
• Combining separately recorded audio and video files

Fix in VLC (temporary, for playback):

• Audio ahead of video: press J to delay audio (up to 500ms per press)
• Audio behind video: press K to advance audio

Fix permanently in HandBrake:

1. Open the video in HandBrake
2. Audio tab → Gain/DRC → look for the audio track offset setting
3. Set the offset in milliseconds (negative to delay, positive to advance)
4. Encode

Type 2: Drift (Gets Progressively Worse)

The sync starts correct but gradually drifts — by the end of a long video, the audio may be several seconds off. This is caused by mismatched audio and video frame rates.

Common cause: Variable Frame Rate (VFR) video — typically from screen recordings or smartphone recordings — where the frame rate is not constant. Most editors assume Constant Frame Rate (CFR).

Fix: Convert from VFR to CFR using HandBrake:

1. Open HandBrake → Video tab
2. Framerate: select a fixed rate (29.97 or 30 fps for NTSC; 25 fps for PAL)
3. Enable "Constant Framerate" option
4. Encode

Type 3: Sync Issues in Browser Playback Only

If the video plays correctly in VLC or Windows Media Player but is out of sync in Chrome or Safari, the issue is browser-specific decoding.

Fix: Re-encode using HandBrake to standard H.264 + AAC in an MP4 container — the most browser-compatible format.

Quick Test: Is the Original File Out of Sync?

Open the file in VLC. If it is in sync in VLC, the problem is the player or platform you are using, not the file itself. If it is out of sync in VLC, the file itself has the sync issue.

Frequently asked questions