Free tool
Sync audio and video in your browser
Drop two recordings of the same session, such as a camera file and a mic recording, or two cameras. The tool compares their sound and tells you how far apart they started, in seconds, milliseconds and frames. It runs in your browser, so nothing is uploaded and you need no account.
Find the offset
Your files stay on this device: they are read and compared by your browser and never uploaded.
- WAV, AIFF, and MOV or MP4 with PCM or AAC audio (most cameras and recorders): any file size. We read the first 10 minutes of each.
- Other formats your browser can play, such as MP3 or FLAC: up to 50 MB each.
- Each file needs at least 10 seconds of sound, and the two must overlap in time.
How it works
- Your browser reads the audio from each file and keeps the speech range, so hum and hiss matter less.
- It turns each recording into a pattern of loudness over time, and slides one pattern along the other to find where they match best.
- It checks that match at the start, middle and end of the overlap, then refines it on the sound waves when both files heard the same sound.
- You get the offset, which file started first, a confidence rating, and the offset in frames at common frame rates.
It is the same method podswitch uses to sync every file in a multicam podcast, trimmed down to run on one pair of files in a browser. Read more in how podswitch syncs cameras and audio.
How to apply the offset in your editor
In every editor the idea is the same: put both clips at the same start, then move the clip that started recording later by the offset. Use the frame count or timecode for your timeline’s frame rate from the table in the result.
Final Cut Pro
- Select the clip that started recording later in the timeline.
- Press the Plus Sign (+) key, type the offset as timecode, and press Return. The clip moves later by that amount.1
- Final Cut Pro trims the neighbouring clips to make room. To leave a gap instead, press P for the Position tool before typing the timecode.1
Final Cut Pro can also sync clips itself: select them in the browser, choose Clip > Synchronize Clips, and select “Use audio for synchronization”.2
Premiere Pro
- Place both clips at the very start of the sequence.
- Select the Playhead Position timecode, type the offset, and press Enter (Windows) or Return (macOS) to move the playhead there.3
- Drag the clip that started recording later until its start lines up with the playhead.4
Premiere Pro also has Clip > Synchronize, which lines up selected clips by their start, end, timecode, a clip marker, or an audio track you choose as the reference.4
DaVinci Resolve
Put both clips at the start of the timeline, then move the clip that started recording later by the offset, using the frame count for your timeline’s frame rate.
Questions
Are my recordings uploaded?
No. The files are read and compared by your browser, on your device. The files are not sent to podswitch or anyone else, and nothing is kept after you close the page. You do not need an account.
Which files can I use?
WAV and AIFF files, and MOV or MP4 files with PCM or AAC audio, which covers most cameras, phones and audio recorders, at any file size. Other formats your browser can play, such as MP3 or FLAC, work up to 50 MB each. Each file needs at least 10 seconds of sound.
How long can the recordings be?
Any length, but the tool compares the first 10 minutes of each file to keep it quick on laptops and phones. The two recordings need to overlap within those minutes, which they do when both were started around the same time.
How accurate is the offset?
When both files picked up the same sound, for example a camera microphone and a lavalier in the same room, the match uses the sound waves themselves and is accurate to a fraction of a millisecond. When they do not, for example a remote guest recorded through a call, the match uses the pattern of loudness and is accurate to a few milliseconds. Both are well inside one video frame.
What does the confidence mean?
The tool measures the offset at the start, middle and end of the overlap. High confidence means a clear match that agrees at all three points. Medium means a match was found but is less clear-cut. Low means the recordings may not be from the same session, or share too little sound, so check the result by ear before relying on it.
Why does the sync slip by the end of the recording?
Separate recorders can run at very slightly different speeds, so two files that line up at the start can drift apart over a long session. If the tool sees the offset change between the start and the end, it tells you by how much per hour.
Can podswitch sync my cameras automatically?
Yes. When you make a multicam edit with podswitch, it compares the sound of every camera and microphone file, checks the sync at the start, middle and end, and then cuts the edit from the microphones for Final Cut Pro, Premiere Pro or DaVinci Resolve.
Sources
Checked on 31 October 2026. Menus and shortcuts can change between versions.
Syncing is only the first step.
podswitch syncs every camera and microphone in a session by their sound, then cuts the multicam edit from the mics and hands it to Final Cut Pro, Premiere Pro or DaVinci Resolve. Your video stays on your computer. See how it works.