How to Sync Audio and Video in DaVinci Resolve 21

Quick answer: for a camera clip with scratch audio and a matching external WAV, select the pair, or their organized bins, in the Media Pool, right-click, and choose Auto Sync Audio. Set Synchronize Using to Waveform. Enable Retain embedded audio when you want the camera scratch track to remain beside the production recording, then click Sync. Inspect the associated audio channels, listen around the clap, and check the beginning, middle and end of a long take before editing it into a timeline.

That last check matters. Auto Sync can find an initial match; it can't make two unsynchronized recorder clocks run at the same speed. A constant offset, a failed waveform match and drift that grows over time are three different problems.

The menu names and sync behavior were checked on September 5, 2026 against the DaVinci Resolve 21 Reference Manual. For the surrounding editing steps, the Resolve Workflow hub covers ingest, proxies, multicam and project organization.

Choose the sync method from the reference you actually recorded

Multicam isn't required for one camera and one external recorder. Use the Resolve multicam guide when the job is synchronizing several camera angles and switching between them; use this page when the primary job is attaching production audio to source video.

Auto-sync by waveform in Resolve 21

1. Put only the matching camera and audio files in one bin, or multi-select the corresponding video and audio bins. Smaller day or scene groups reduce false candidates and analysis time.
2. Right-click the selected clips or bins and choose Auto Sync Audio.
3. Set Synchronize Using to Waveform.
4. Leave Use channel number on Auto for the first test. Choose Mix or the specific channel carrying the useful reference when other channels are silent or noisy.
5. Enable Retain embedded audio if you want camera scratch audio available after sync.
6. Enable Retain Video Metadata only when the camera's scene/take metadata must win over matching metadata in the audio file.
7. Click Sync, note any clips Resolve reports as unmatched, then verify a successful pair.

Waveform matching needs common recorded sound. A camera file with no usable reference audio cannot supply a match; a muted timeline track is not the same as a silent source file. Heavy clipping or noise can make matching less reliable. Re-recorded ADR won't reliably match the original performance just because the words are the same.

Retain Embedded Audio vs the old “Append Tracks” wording

Older Resolve tutorials often present two commands: replace the camera audio or choose “Based on Waveform and Append Tracks.” The current Resolve 21 dialog expresses that decision with Retain embedded audio.

• Retain off: the newly synced production audio replaces the video clip's previous audio-channel result.
• Retain on: Resolve adds the production channels while keeping the original camera audio available as additional channels/tracks when the clip is edited.

Neither choice deletes the camera source file or external WAV from disk. It changes the audio associated with the synced Media Pool clip. Right-click the synced clip, open Clip Attributes > Audio, and inspect the channel mapping instead of assuming a second timeline lane contains the right microphone.

Batch-sync by timecode

Use Timecode when camera and sound recorder were jam-synced or otherwise recorded matching code. Right-click the organized bins, choose Auto Sync Audio, select Timecode, decide whether to retain embedded audio and video metadata, then Sync. If several Broadcast WAV files overlap with matching code, Resolve can add each match; the preference Limit media pool audio sync to first timecode match in Preferences > User > Editing restricts that behavior when appropriate.

Matching numbers do not prove the devices were actually synchronized on set. Spot-check the slate and lips. If the code is consistently wrong, switch to waveform or a marked clap rather than trusting metadata because it looks professional.

Manually sync a clap in the Media page

1. On the Media page, set the Audio Panel to Waveform before selecting the source clips.
2. Select the camera clip and park the Viewer on the frame where the slate closes, a hand clap lands or another sharp visual cue occurs.
3. With the video Viewer parked there, select the matching WAV in the Media Pool. Its waveform opens in the Audio Panel.
4. Scrub the audio to the corresponding sharp spike. Listen to confirm the event; a nearby peak could be room noise rather than the clap.
5. Before linking, open the Audio > Waveform three-dot menu. Set Retain embedded audio and Retain video metadata according to what you want to keep.
6. Click Link/Unlink Audio in the Audio Panel to attach the aligned recording to the video clip.

You can also mark matching In points, Out points or Markers on one video/audio pair, then choose Audio Sync > Auto Sync Audio and select that point type. Both clips need the same kind of point. This is still a manual identification step, but Resolve performs the final association consistently.

Sync clips already on the timeline with Auto Align

Media Pool Auto Sync changes the source clip's audio association for future edits. Auto Align Clips moves items already arranged on the timeline. Put one clip per track, make sure their timecode or waveforms overlap, select them, right-click, and choose Auto Align Clips > Based on Timecode or Based on Waveform.

All selected clips align to the selected clip on the lowest-numbered video or audio track. Clips without overlapping timecode or matching waveforms stay where they are and appear in the warning. When waveform alignment prompts for a reference track, choose the recording whose waveform should be compared. Check the result before continuing to edit.

Verify the sync before cutting

1. After Auto Sync finishes, note any clips reported as unmatched.
2. Open Clip Attributes and confirm the intended production channels are mapped.
3. Listen to the slate or first hard consonant with camera scratch and production audio both available.
4. Check lips, impacts or another clear event near the beginning.
5. Check identifiable events in the middle and near the end of a long take. An audio badge alone is not a sync check; confirm the recorder channels and listen.

A fixed offset is not drift

If the audio is early or late by the same amount at the beginning, middle and end, correct the fixed offset instead of stretching the recording. Resolve 21 provides Trim > Slip Audio commands for whole-frame moves and 1/10-frame subframe moves. Use a clear transient or consonant, make the smallest correction that solves the mismatch, then check all three points again.

If a slate is hard to locate in a large shoot, the Resolve 21 Slate Finder guide explains how to locate slates and use their metadata. Still listen to the matched result before you start cutting.

Why Auto Sync fails

No matching reference audio

Waveform sync can't match silence, unrelated room tone or a different performance. Use timecode, matching markers/In-Out points or a manual visual/audio cue.

The useful sound is on another channel

Set Use channel number to the actual scratch channel, or try Mix when one channel contains long gaps. Don't analyze a noisy channel merely because it's channel 1.

Too many unrelated files are selected

Separate media by day, scene or known pair and rerun the failed clips in smaller batches. Resolve's completion warning identifies pairs that need another method; it isn't evidence that every file in the batch failed.

The clip synced but plays no sound

Inspect Clip Attributes, track mute/solo, bus routing and output. If unrelated timeline clips are silent too, leave the sync workflow and use the Resolve no-audio diagnostic.

Audio starts in sync, then drifts

If the clap matches at the start but lips are late at the end, one offset cannot fix both points. Check an event in the middle, too. A steadily growing gap suggests drift; a sudden jump calls for inspection around that point. Two endpoint checks alone do not tell you which problem you have.

Independent device clocks can cause progressive drift even after a correct starting alignment. Sound Devices explains why locking recording clocks prevents drift. Irregular source timing or dropped/duplicated frames are other possibilities to investigate, not a diagnosis you can make from the file extension.

Resolve defaults project audio to 48 kHz and automatically resamples imported audio with other sample rates to the timeline rate. A 44.1-versus-48 kHz difference alone does not establish the cause of drift.

A variable-frame-rate phone or screen recording is worth checking when its timing appears irregular, but VFR alone is not proof of a fault. If source timing is implicated, preserve the original and test a constant-frame-rate copy.

For a measured, steady rate mismatch, a controlled duration correction may be appropriate. Check several events afterward; one stretch will not repair every discontinuity.

Only the rendered file is out of sync

If the timeline stays aligned but the delivered file doesn't, don't repeat Media Pool Auto Sync. Re-import a short render into Resolve and compare a visible impact or spoken consonant against the source timeline. A correct re-import points toward the external player or delivery path. If the re-import is wrong too, investigate the rendered file and export settings. The Resolve export hub helps you check codecs, export audio and delivery settings once the source pair is stable.

Don't change the project timeline FPS to repair one drifting take. The Resolve frame-rate guide explains when to set timeline rates. For a single drifting take, investigate the source recordings first.

Free vs Studio

Media Pool Auto Sync, waveform/timecode methods, manual linking and timeline Auto Align are documented without a Studio-only marker. The core workflow therefore applies to Free and Studio. Hardware timecode, recorder accuracy and the quality of camera scratch audio affect the result more than the edition badge.

After sync, the Fairlight audio hub can help with cleanup, EQ, dynamics, buses and loudness. First confirm that the correct recording stays aligned for the whole take; then start mixing.

DaVinci Resolve audio and video sync FAQ

How do I auto-sync audio and video in DaVinci Resolve 21?

Select the matching camera and audio clips or bins in Media Pool, choose Auto Sync Audio, select Waveform or Timecode, decide whether to retain embedded camera audio and video metadata, then click Sync and verify the result.

Should I use Waveform or Timecode?

Use Timecode when camera and recorder captured genuinely synchronized code. Use Waveform when both files contain the same reference sound. If neither exists, use matching markers/In-Out points or align a visible clap manually.

What happened to “Based on Waveform and Append Tracks”?

Current Resolve 21 presents that choice as Retain embedded audio in the Automatically Sync Audio dialog. Enable it to keep camera audio alongside newly synced production channels.

How do I sync clips already on the timeline?

Put one selected clip per track with overlapping timecode or audio, then choose Auto Align Clips based on Timecode or Waveform. Resolve aligns the selected items to the lowest-numbered selected track. Choose the waveform reference track if prompted, then verify the alignment.

Why does waveform sync fail?

The sources may lack matching sound, the useful reference may be on another channel, or the batch may contain unrelated files. Select the correct channel or Mix, reduce the batch, or use timecode, markers or manual clap sync.

Why is audio synced at the start but not the end?

Check events near the beginning, middle and end. A steadily growing offset suggests drift; a sudden jump may indicate a timing discontinuity. Investigate device clocks and source timing before applying a duration correction. One fixed offset cannot correct a changing gap.

Does Auto Sync delete the original camera audio?

No source media is deleted. Retain embedded audio controls whether the camera channels remain associated alongside the synced production audio. The original camera file and external WAV remain on disk.

Jason Miller I run DaVinci Resolve Club as an independent publication: hands-on edits, color grading breakdowns, Fairlight sessions, Fusion tests, and honest notes on where Resolve gets in the way.