Finding a loop by ear is slow. You scrub, you guess, you miss the downbeat by a few milliseconds, and the seam clicks. Loop Finder is built for that one job: find the places in a track that can repeat cleanly, let you hear them, then export the clip.

Open the app, sign in, and start a trial. Upload a file. Set how short or long a loop may be. Tap Find loops. Then preview candidates on a waveform, nudge the start and end, save the keepers, and download MP3s.

Why we built it

Producers, game-audio people, and short-form video editors all need the same thing: a section that can play forever without an obvious join. Most editors make you hunt those points by hand. We wrapped a serious loop detector in a browser UI so you can do the hunt on a laptop or a phone and leave with a file, not a screenshot of a timeline.

1. Detection you can steer

After you pick an audio file, you set three controls before the search runs:

• Min duration — ignore loops shorter than this (default 5 seconds)
• Max duration — ignore loops longer than this (default is in the 30–45 second range)
• Loop count — how many candidates to return (default 20)

Those knobs matter. A 4-bar hook and a 30-second ambient bed are different searches. You can save your usual defaults in account preferences, and optionally remember the last values you used on the main screen.

The backend runs PyMusicLooper and returns start time, end time, and a score for each candidate. You are not staring at raw timestamps in a terminal.

2. Hear it on the waveform before you commit

Detection is only half the product. Each candidate can be previewed on an interactive waveform. You see start, length, and end. You can zoom, fit the wave, play the loop, stop it, and nudge start or end by hundredths of a second.

That last part is the difference between “almost” and “usable.” A mathematically good loop still needs a pair of ears. The UI is there so you can tighten the seam without dropping into a DAW.

The mobile layout uses a Material-style interface and WaveSurfer. The desktop layout uses a Plotly waveform. Same job, two surfaces: phone at https://api.sonicloops.cloud/, desktop at /desktop.

3. Save clips, rename them, export MP3s

When a loop is right, you can bookmark it or download it immediately as MP3. Encoding happens in the browser. Saved clips sit in a dock at the bottom of the mobile UI: rename them, reorder them, jump back to one from a chip row, or export the whole set.

Clips are stored locally in the browser, keyed to the file you uploaded. Clearing them is explicit. You are not silently filling a server library with every experiment.

4. An account, a trial, and a subscription when you are ready

Loop Finder is a hosted AppHaven service. You create an account (email, or Google when it is enabled), then start a free trial to unlock detection, waveform preview, and export. From the account sheet you can see subscription status, trial end date, and a manage-subscription link.

That is the SaaS half of the studio: a tool you open in a browser, not another installer.

Who it is for

• Music producers hunting intros, drops, and one-bars that will actually loop
• Game and app audio people who need beds and stingers that can repeat
• Video and social editors who want a seamless music bed without a DAW session
• Anyone who has ever dragged loop points by a few milliseconds and still heard the click

Try it

Loop Finder is live at https://api.sonicloops.cloud/. Create an account, start the trial, and drop in a track you are allowed to process. Questions or studio licenses: projects@apphaven.net.