VLC Audio Delay: Fix Out-of-Sync Sound

Updated 6 November 2026 · Standard formula, shown below

If your audio is out of sync with the video in VLC, you can fix it by adjusting the audio track synchronization setting, either temporarily with hotkeys or permanently for a specific file via the Synchronization menu. This article explains both methods, how to save your adjustments, and why the delay happens in the first place.

Why Audio and Video Get Out of Sync

Audio-video desynchronization in VLC usually stems from one of three causes: the source file itself has a sync error, your system’s audio hardware introduces latency, or the video codec is demanding more processing power than your device can deliver. When a file is encoded, the audio and video streams are stored separately; if the encoder or a remuxing tool misplaces timestamps, the streams start at slightly different times. On playback, VLC reads these timestamps and tries to present frames and sound together, but any mismatch in the timestamps becomes a visible delay. Hardware latency is common with Bluetooth speakers or headphones, where the wireless transmission adds a fixed delay that VLC cannot automatically detect. Heavy video processing, such as playing a 4K file on an older computer, can also cause the video to drop frames while audio continues uninterrupted, creating a lag that grows over time.

Quick Fix: Adjusting Delay During Playback

VLC provides two keyboard shortcuts that let you nudge the audio delay in real time without opening any menus. While a video is playing, press the K key to increase the audio delay (audio plays later) and the J key to decrease it (audio plays earlier). Each press changes the delay by 50 milliseconds. If you need a larger jump, hold the key down to repeat the action. This is the fastest way to test whether a small correction fixes the sync issue. For example, if the sound seems to come 200 ms before the lips move, press J four times to shift audio later. You can also use the menu: go to Tools > Track Synchronization and drag the “Audio track synchronization� slider. The slider shows the current delay in milliseconds, with positive values meaning audio is delayed relative to video.

Permanent Fix: Saving the Delay for a File

The temporary adjustment only lasts for the current playback session. To make the correction stick every time you open that file, you need to save it in the file’s metadata. Here’s how:

Start playing the file and adjust the audio delay using the K/J keys or the Track Synchronization slider until the sync is perfect.
Go to Tools > Track Synchronization again.
Note the value in the “Audio track synchronization� field (it may be negative or positive).
Click the Save as default for this media button. VLC stores this value in its internal database, keyed to that specific file’s identity.

Next time you open the same file, VLC will apply the saved delay automatically. This does not modify the original file itself, so your source remains untouched. If you later move the file to another computer, you’ll need to set the delay again because the setting is stored locally in VLC’s configuration, not in the file.

Setting a Global Default Delay

If you consistently use a Bluetooth speaker that adds a fixed delay, you might want to apply a default offset to all videos, not just one file. In VLC, go to Tools > Preferences (or press Ctrl+P). At the bottom left, select All to show advanced settings. Then navigate to Input / Codecs and look for the “Audio desynchronization compensation� field. Enter a value in milliseconds; positive values delay audio, negative values make it earlier. For instance, if your Bluetooth speaker always lags by 150 ms, enter -150 to compensate. Click Save, restart VLC, and the offset will apply to every video you play. Be careful: this global setting will also affect files that were already perfectly synced, so only use it if the same hardware is always connected.

Common Problems and What They Mean

Sometimes the delay persists even after you set a value. Here are a few common situations:

Delay changes during playback: If the sync drifts progressively (starts fine, gets worse), the issue is likely performance-related. Try lowering the video resolution, disabling hardware decoding, or closing other applications.
Delay is different for subtitles: Subtitle sync is a separate setting. In the Track Synchronization window, you’ll see a “Subtitle track synchronization� field. Adjust it independently if subtitles are out of sync.
Delay resets after restart: If you used the K/J keys but didn’t save, the delay will reset. Use the “Save as default for this media� button.
Only one file is affected: The file itself may have a bad encode. Re-encoding the file with a tool like HandBrake can fix it permanently, but that’s a heavier solution.

Advanced: Using the Command Line

For users comfortable with the command line, VLC can start with a pre-set audio delay using the --audio-desync option. For example, to open a file with a 300 ms delay, run:

vlc --audio-desync 300 movie.mp4

This is useful for scripting or when you want to test different values without touching the GUI. The value is in milliseconds, and negative numbers are allowed. Note that this option only applies to the current session; it does not save anything.

Frequently Asked Questions

What is the default audio delay in VLC?

By default, VLC has no audio delay (0 ms). The synchronization is based on the timestamps in the file. If you see a delay, it’s either in the file itself or caused by your playback hardware.

How do I fix audio delay in VLC on Mac?

The same hotkeys (J and K) work on macOS, but you may need to use the Option key if you have function keys enabled. Alternatively, go to Tools > Track Synchronization and drag the slider. The process is identical to Windows.

Why does my audio delay get worse over time?

This usually indicates a performance problem. When the video decoder can’t keep up, it drops frames, causing the audio to drift ahead. Try reducing the video output quality or disabling hardware acceleration in Preferences > Input/Codecs.

Can I save the audio delay directly into the video file?

VLC does not write changes to the original file. To permanently embed a delay, you would need to remux the file using a tool like MKVToolNix or re-encode it. VLC’s “Save as default for this media� only stores the setting locally.

Does the audio delay setting affect all videos?

No. The per-file setting only applies to the specific file you saved it for. The global “Audio desynchronization compensation� in Preferences applies to all videos, but it’s off by default.

What if the audio is ahead of the video by a large amount?

You can press J repeatedly to reduce the delay, or set a negative value in the Track Synchronization window. For example, if audio is 1 second early, set the value to -1000 ms.

Method: the standard formula for this calculation, rounded as each result states. See how the calculators work or report an error.