Hi Product Hunt,

I shoot video for a living, in Malaysia. For years my sync workflow was PluralEyes - drop the cards in, let it line everything up, keep editing. It is not being developed any more, and every few weeks somebody asks the same question I was asking: what do we use now?

So I built it. Synfren listens to the sound every camera and recorder already captured, works out where they overlap, and writes the timeline out - FCPXML for Final Cut Pro, FCP7 XML for Premiere Pro and DaVinci Resolve.

The part I actually care about is not speed. It is knowing what to check.

A tool that places 100 clips and is quietly wrong about 4 of them has saved you nothing, because you still have to scrub all 100 to find the 4. So every clip in Synfren says what its placement is worth:

- heard: measured from the sound itself

- clock-checked: nothing usable to hear, so it was carried by the camera's clock, and that clock was verified against clips that were heard

- needs attention: it would be guessing, so it does not place it

You look at the third pile. And a sync that did not finish cannot be exported as though it had.

How close it gets. My rule: a clip placed from sound lands within 100 ms of where the sound says it belongs, or Synfren does not place it at all. A frame at 25 fps is 40 ms. Measured on one of my own weddings, against an answer worked out independently from the sound alone:

- placed from sound: median 0.3 ms, worst 7.9 ms (about a fifth of a frame)

- carried by a camera clock: good to about a second, and labelled that way

- could not be placed: left for me, never guessed

Your footage stays on your Mac. Working out the offsets happens partly on a server, but what goes there is compact loudness data - never your video, never your audio, never a filename or a folder name - and it is deleted when the job ends.

Where it is today: macOS 14 or later, Apple silicon. Signed and notarised. No Windows yet, no Avid, no Intel build.

Free to try - three exports with every account, and syncing is never counted, because a synced project delivers nothing until you export it. Plans start at $5.

I have exactly one Mac to test on, an M1 Air, so if it breaks on yours I want to hear about it. The app asks after every sync whether it came out right, and that is where the next build comes from.

https://synfren.com

For Product Hunt: the first 20 people to type PRODUCTHUNT at https://synfren.com/redeem get a month of exports, free. It starts when you claim it, not today, and there is no card to add.

Happy to answer anything here, including what it is bad at.

- Martin