Put every recording in sync
Line up every camera and microphone from one event — automatically, to the millisecond.
For researchers, and everyone else
Several recordings, one event, and none of them start at the same time.
A classroom filmed from two corners. An interview with a camera and a lapel mic. A focus group, a performance, a lab session. Every device was switched on at a slightly different moment, and before you can compare or analyse them, they have to line up.
Lining them up by hand
Slow and never quite right
Scrubbing back and forth looking for a clap, one file at a time. Then the recordings slowly slip apart anyway, because no two devices keep exactly the same time.
Professional editing software
Expensive, and built for something else
Editing suites can sync clips, but they cost money, take weeks to learn, and are designed to cut one film — not to hand back each recording as its own file, ready for analysis.
Media Alignment Tool
Automatic, precise and free
Add your recordings and press one button. The app listens to each one, works out where it belongs, and exports every file trimmed to the same start and end — so the same moment has the same timestamp everywhere.
How it works
From a pile of files to synced recordings in four steps
Add your recordings
Video from any number of cameras, audio from any recorder or phone. Files a camera split into chapters can be joined first.
Press Align
The app compares the sound in each recording and slides every one into place on a shared timeline.
Check it
Watch every angle play together, read the report of how confident each match is, and fine-tune if you want to.
Export
Every file comes out the same length, starting and ending at the same instant — in the format you choose.
What you get
Everything needed to sync, nothing you have to learn first
Automatic alignment from sound
No clapperboard needed. The app matches the everyday sound that every microphone heard — voices, footsteps, room noise — and tells you how confident it is about each match.
Fixes clocks that run fast or slow
Cheap recorders drift: one that gains two seconds an hour ends a long session badly out of step. The app measures that drift and corrects it, so the end lines up as well as the start.
Sync by marking a moment
When the sound is too different to compare, mark the same instant — a clap, a door closing, a light switching on — in each recording, and the app lines them up from your marks.
Watch every angle at once
All cameras play side by side from one clock, with sound from whichever microphones you pick. Zoom into any view to check a detail. Formats that won't play directly get a preview copy made automatically.
Exports that stay in sync
Every output starts and ends at the same instant and is exactly the same length. Keep each file's original quality, or choose a format, size, frame rate and quality per recording — and save your choices as presets.
Joins split camera files
Action cameras like GoPro break long recordings into several files. Merge & Add Media puts them back in recording order and joins them into one — usually without re-encoding, so nothing is lost.
Opens MP4, MOV, MKV, AVI, MTS/M2TS (AVCHD), MXF, WebM, WAV, AIFF, MP3, FLAC, M4A and more. Media processing powered by the open-source ffmpeg.
Precision you can check
Measured, not guessed
When your analysis depends on knowing exactly when something happened in each recording, "close enough" isn't. {{PRODUCT_NAME}} shows its working, so you can trust the result — or see straight away which recording needs a second look.
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A report for every runEach recording gets a confidence score, the number of moments it was matched on, and the drift that was corrected — with a plain warning when something looks doubtful.
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The evidence stays on the timelineThe matched moments are left as markers, so you can jump to any of them and see — and hear — that the recordings really do agree.
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Nothing is final until you exportEvery change can be undone, work is autosaved, and your original files are never modified.
Accuracy in testing
| Measured | Result |
|---|---|
| Start time | Within 1 ms |
| Clock drift | Within 7 ppm (≈ 25 ms per hour) |
| How far apart recordings can start | 5 minutes by default — adjustable |
Checked against simulated recordings of one event made by five "microphones" with known start times, clock speeds, room echo and background noise — so the right answer is known exactly, not estimated.
Sync your next session in minutes
Free to download. No account, no subscription, no upload.