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. Check the audio badge, listen around the clap, and compare the beginning and end before editing the clip 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 controls and behavior below were rechecked on August 27, 2026 against the current DaVinci Resolve 21 Reference Manual. This page owns dual-system audio synchronization. The Resolve Workflow hub connects it to ingest, proxies, multicam and project organization without repeating those full tasks here.
Choose the sync method from the reference you actually recorded
| Reference available | Resolve method | Best use |
|---|---|---|
| Camera and recorder share synchronized timecode | Auto Sync Audio > Timecode | Fast batch sync for organized production sound and Broadcast WAV files. |
| Camera scratch audio matches the external recording | Auto Sync Audio > Waveform | Single-camera interviews, podcasts and location work without matching timecode. |
| Both clips have a matching In, Out or Marker | Auto Sync Audio > In / Out / Marker | One pair at a time when there is a known clap or cue but waveform analysis fails. |
| A visible clap and audio spike | Manual Media-page sync | Precise pair-by-pair control and difficult recordings. |
| Clips are already placed on separate timeline tracks | Auto Align Clips | Move overlapping timeline items to the lowest-numbered selected reference track. |
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
- 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.
- Right-click the selected clips or bins and choose Auto Sync Audio.
- Set Synchronize Using to Waveform.
- Leave Use channel number on Auto for the first test. Choose Mix or a specific channel when the useful camera reference is missing or noisy on other channels.
- Enable Retain embedded audio if you want camera scratch audio available after sync.
- Enable Retain Video Metadata only when the camera's scene/take metadata must win over matching metadata in the audio file.
- Click Sync, note any clips Resolve reports as unmatched, then verify a successful pair.
Waveform matching needs common sound. If the camera file is MOS, muted, badly clipped or contains a different performance, there's nothing precise to compare. Re-recorded ADR also will not waveform-match the original dialogue just because the words are similar; the waveforms must correspond.
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 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
- 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.
- Open the matching WAV in the Audio Panel and switch the panel to Waveform.
- Scrub to the corresponding sharp audio spike. Zoom enough to avoid choosing room noise just before or after the clap.
- Click the Link/Unlink Audio button in the Audio Panel to attach the aligned audio 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 waveform stay where they're and appear in the warning. This makes track order part of the command, not cosmetic organization.
Verify the sync before cutting
- Look for the audio badge on the synced Media Pool thumbnail.
- Open Clip Attributes and confirm the intended production channels are mapped.
- Listen to the slate or first hard consonant with camera scratch and production audio both available.
- Check lips, impacts or another clear event near the beginning.
- Check a second event near the end of a long take.
A fixed offset is not drift
If the audio is early or late by the same amount at both ends, 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 verify both ends again.
If a slate is hard to locate in a large shoot, the Resolve 21 Slate Finder guide owns discovery and metadata. It doesn't replace listening to the matched result.
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, moving the whole audio clip can't fix both points. That's drift, not a constant offset. Compare the same identifiable event near the beginning and end before changing speed or cutting the track.
Common branches include independent recorder clocks, variable-frame-rate phone or screen recordings, or dropped/duplicated frames. Resolve defaults project audio to 48 kHz and automatically resamples imported audio with other sample rates to the timeline rate, so “44.1 versus 48 always causes drift” isn't an adequate diagnosis. Normalize unstable variable-rate media when evidence points there; for a small steady clock difference, measure the start/end gap before making a controlled duration correction.
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 to the external player or delivery path; a wrong re-import points to the render itself. The Resolve export hub owns codec, audio and delivery checks after the source pair has been proven stable.
Don't change the project timeline FPS to repair one drifting take. The Resolve frame-rate guide owns timeline-rate decisions; drift between independently recorded devices belongs to source timing and verification.
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 routes cleanup, EQ, dynamics, buses and loudness. Keep synchronization separate from mixing: first prove the right performance is attached and stable for the whole take.
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.
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?
A growing gap is drift rather than one fixed offset. Check independent recorder clocks, variable-frame-rate media and dropped frames, then measure the gap at both ends before applying a duration correction.
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.
