Audio and video out of sync?

Before moving a track, play the same local video in another media player. Use the same speakers or headphones for both tests. Check a recognizable moment near the beginning, middle and end, and write down what you see and hear.

If it looks right in one player but wrong in another, investigate that playback path first. A player’s audio-delay control can help you test an offset, but hearing a corrected version in that player does not establish that you have saved a corrected video.

If the problem appeared after an export, compare the source and exported copy in the same player. This changes one variable at a time: first the player, then the file. Vimeo’s troubleshooting guidance uses this kind of source-versus-converted-file comparison to distinguish conversion differences from playback differences.

For a recording used in casework, keep a short note of the file, player and timestamps checked. A description such as “sound arrives after the visible clap at 00:18 and 24:10” is more useful than “the lip sync is bad.”

These observations guide the investigation. They do not identify the cause on their own. A video may also contain more than one kind of mismatch.

For a constant offset, find an event that can be identified in both picture and sound. A visible clap or a clear contact sound can give you a better reference than a vague impression that speech feels late. Confirm that the sound belongs to the event you can see.

1. Make a duplicate project or working copy. Keep any camera reference audio and separate recorder tracks available.
2. Put the relevant video and audio on separate tracks in your editor. Note which track you are moving.
3. Locate the visible event and its matching sound. Zoom in enough to make a deliberate adjustment.
4. Move the audio earlier if it arrives late, or later if it arrives early. Make a small change and play it back.
5. Record the direction and amount of the adjustment. Check a different event later in the recording before treating the offset as consistent.

Automatic synchronization can help when the clips share usable audio or timing information. In Premiere, Clip → Synchronize offers synchronization points such as clip starts, common timecode, markers and a reference audio channel. In Final Cut Pro, Clip → Synchronize Clips can use audio waveforms and other sync points to create a synchronized clip while leaving the original clips unaffected.

Do not assume an automatic result is correct. Apple notes that some audio is unsuitable for waveform synchronization and that clips without usable sync points can be aligned at their starting points. Listen and watch the result.

A single track shift moves the whole track by the same amount. It cannot, by itself, correct a mismatch that keeps increasing. Aligning the beginning can leave the end out of sync; aligning the end can disturb the beginning.

Keep the original files and record the properties shown by your editor or media-information tool: video frame rate, whether the frame rate is variable, audio sample rate, clip duration and the sequence or export settings. If audio and video came from different devices, note that too. Those details help an editor investigate the mismatch without guessing at a universal setting.

Variable frame rate is one possible consideration, particularly when a problem appears during editing or conversion. Vimeo recommends constant frame rate for its uploads. That is guidance for that delivery workflow, rather than a reason to change every recording to a particular frame rate.

Changing how footage is interpreted can alter its timing. Adobe’s current documentation states that changing a clip’s interpreted frame rate changes both its duration and its audio. Keep that separate from a deliberate export or conversion, and avoid trying frame-rate numbers until the picture appears to match.

If correction requires stretching audio, changing playback speed or treating sections separately, retain a separate version and document the work. For consequential recordings, ask what can be assessed before making those changes yourself.

The editor’s preview is only one check. Export a separate test file and open it outside the editor.

• Check clear sync events near the beginning, middle and end.
• Watch across cuts, pauses and any place where the timing changed abruptly.
• Confirm the intended audio track is present and that you have not left a second copy playing underneath it.
• Check the opening and closing content for accidental trimming or added gaps.
• Review the full exported recording, including the sections between your checkpoints.
• Keep the source, project or adjustment notes, and corrected export distinguishable by name.

If the export differs from the preview, compare them before making another timing change. Otherwise, you may compensate for one problem while introducing a new one.

If you need help assessing a recording, explain where the mismatch first appears, whether it stays constant or grows, and whether it occurs in the original file, a particular player or an export. Keep the original video and separate audio files available.

Media Medic’s video cleanup page explains what to include in a review request. Describe the synchronization issue and confirm what work is possible before proceeding.

Request a file review

Read about video cleanup