How many cameras can I sync at once?
Up to eight files in one project: any mix of cameras and sound recorders. Larger shoots can be done in batches that share one reference camera.
Free · runs in your browser
Sync multiple cameras by their sound
Drop every angle and every recorder from one shoot. They’re matched by what they all heard, shown on one timeline, and saved as synced files or a ready-made editing timeline.
To sync several cameras, drop all their clips here together, along with any separate audio recorder. Every file is compared with the first camera by the shape of its sound, placed at the right offset on a shared timeline, and checked for clock drift, usually within a few seconds.
From there you choose what to take away. Export synced copies rewrites each file so they all begin at the same moment, which makes them line up in any editor at frame zero. The FCPXML (Final Cut, Resolve) and XML (Premiere) buttons write a timeline with every clip already on its own track, ready for a multicam edit. Or pick one angle and Export video with the clean recorder sound in place of the camera’s.
It all happens in your browser, so a card full of 4K rushes never has to be uploaded anywhere. If you only have one camera and one microphone, sync external audio to a video walks through that simpler job, and if a single file’s sound is simply late, fix the audio sync is the place to start.
Sync multiple cameras
Everything in sync multiple cameras
Replace or add sound
- Sync a separate mic or recorder to a video Replace a camera’s scratch sound with a lav, recorder or phone recording, lined up automatically.
- Add music or audio to a video Put a song, voiceover or recording on a clip: mix or replace the sound, set the start, fade out.
In your editing app
- Sync audio and video in Premiere Pro Synchronize, Merge Clips and multicam source sequences, plus fixes when Premiere won’t sync.
- Sync audio in DaVinci Resolve Auto Sync Audio, Auto Align Clips and multicam by sound, and what to do when Resolve can’t sync.
- Sync audio in Final Cut Pro and iMovie Synchronize Clips in Final Cut Pro, lining up by hand in iMovie, and a browser shortcut for both.
Tools and tips
How to sync multiple cameras in sync.video
Drop every file from the shoot
Drag the camera clips and any recorder files onto Drop your video and its sound files, or press Choose files and select them together. Up to eight files work at once; you can bring in more later with Add files (Ctrl/Cmd+O).
Check the matches
Each file gets a chip saying Sure match, Likely match or Unsure. Press Show all angles (G) and play a moment with a clap or a hard consonant to see and hear every camera at once. For an unsure file, try Try the next match or drag it on the timeline.
Choose the picture and the sound
Press Use this picture on the angle you want as the reference. Under Sound in the new video, choose Replace the camera sound for the recorder, Mix them, Keep both or Keep the camera sound.
Export what your edit needs
Open More options and press Export synced copies, or download FCPXML (Final Cut, Resolve), XML (Premiere) or Offsets (CSV). For a single finished angle, press Export video (Ctrl/Cmd+Enter).
How matching by sound works, and when it fails
Every camera on a shoot hears the same room, so each one’s soundtrack has the same pattern of loud and quiet moments, only starting at a different time. sync.video draws an outline of the sharp attacks in each soundtrack, slides each outline past the first camera’s until the two overlap best, then refines that position on the raw sound to well under a millisecond. Because it compares rhythm rather than tone, a tinny camera microphone still matches a clean lavalier.
What it needs
- Sound in every file. A camera with its microphone switched off, or a drone, has nothing to match; place it by eye on the timeline instead.
- Some overlap in what they heard. Two cameras in different rooms recording at the same time can’t be matched by sound.
- A few distinct moments. Speech, footsteps and claps are ideal. A steady hum, wind or one repeating music loop gives several plausible positions, which is why the chip may say Unsure and Try the next match offers the alternatives.
Drift between cameras
Cameras and recorders each keep time with their own crystal, and over a long take one can run a few parts per million fast. On a two-hour concert that adds up to a visible slip. When files overlap by at least 30 seconds, sync.video measures their offset at several points along the way and, if the gap grows steadily, corrects it by stretching that file’s sound in the export. The list shows how much it found, in parts per million.
Timecode or waveform?
Professional cameras and recorders can share timecode: a running clock written into every file, set from one master or a wireless box. When it is jammed properly, editors line clips up by timecode instantly. It costs money, needs setting up before the take and still drifts on cheap kit if it isn’t re-jammed.
Waveform sync needs nothing on the day except that every device recorded sound. It is how most people sync phones, action cameras, mirrorless cameras and pocket recorders, none of which share a clock. The two approaches also work together: many editors sync by timecode first and use the waveform to check it.
| Timecode | Waveform (sound) | |
|---|---|---|
| Set-up on the day | Jam every device to one clock | None; a clap at the start helps |
| Extra kit | Timecode generators or devices that support it | None |
| Works with phones and action cameras | Rarely | Yes |
| Fails when | A device was not jammed or lost its clock | A device recorded no shared sound |
| Handles drift | Only if re-jammed | Measured and corrected when steady |
What you can take into your edit
Synced copies
Export synced copies saves every file again so that all of them begin at the moment the last camera started rolling. Picture and sound are copied, not re-encoded, so nothing is lost; sound-only files come out as M4A. Drop the copies into any editor at the same start time and they are already in sync.
A timeline file
The timeline buttons write a small XML file that places each original clip on its own track at its offset. Keep it in the same folder as the footage: editors find the media by its file name. One limit is worth knowing: these formats have no way to describe a slow speed change, so drift isn’t carried into the timeline. Offsets (CSV) lists each file’s offset in seconds and frames, plus its drift in parts per million, in case you want to apply a speed change by hand.
One finished video
If you are not editing further, choose the angle with Use this picture, pick the sound and press Export video. The picture is copied as it is; the sound is copied too when it can be, otherwise mixed and encoded once.
Shooting so the sync is easy
- Start every device rolling before the action, and clap once in view of all the cameras. The digital clapperboard turns a phone into a slate whose flash and crack happen in the same instant.
- Leave camera microphones on even when a recorder takes the real sound. Their scratch sound is what the match uses.
- Record at 48 kHz on every device where you can; it saves a conversion later.
- For long events, clap again at the end. If drift creeps in, a second clear moment makes it easier to measure.
If you are used to doing this in an editing app, the guides for Premiere, DaVinci Resolve and Final Cut Pro or iMovie cover their built-in commands, and the PluralEyes alternative page compares the standalone options.
Questions about syncing several cameras
Can I sync two videos of the same event recorded on different phones?
Yes. Drop both and they are lined up by their sound, as long as both phones heard the event. The timeline then shows exactly how far apart they started, and Export synced copies saves both trimmed to the same start.
Do I need timecode?
No. Matching by sound works without any shared clock, which is why it suits phones, action cameras and pocket recorders. If your files do carry timecode, your editor can use that too; the two methods don’t conflict.
What if one camera had no sound?
It can’t be matched automatically. It still appears on the timeline, and you can drag it into place by eye, using a clap or a flash you can see in both pictures.
Will the synced copies lose quality?
No. The compressed picture and sound are copied into the new files with new start times. Only a file whose drift is corrected, or whose sound format the container can’t hold, has its sound encoded again.
Can I edit the multicam in my own software afterwards?
Yes. Download FCPXML (Final Cut, Resolve) or XML (Premiere) and open it in your editor with the footage in the same folder. Every clip arrives on its own track at the right place.
Is anything uploaded?
No. All of the matching, previewing and exporting runs in your browser on your own device.