Privacy Policy

What this policy covers

This policy explains how Audio Trimmer ("the service") handles information when you use the website and its tools, including the browser tools for trimming audio, extracting sound from video, muting clips and removing vocals and background music, as well as the free Windows separation application this site recommends. The service exists for a narrow purpose: local audio processing of files that you own or are licensed to edit. Because that job involves your personal media files, the single most important fact comes first: your media files are never uploaded to us. The rest of this page explains exactly what that means and what small technical interactions do happen.

No account is required to use the service. There is no sign-up form, no user profile, no social layer, and no way for us to identify you across visits. If that ever changes, this page will say so before the change takes effect.

Your media files stay on your device

Every browser tool on this site — the audio trimmer, the extractors, the iPhone video mute, and the preview stage of the stem pages — processes your file inside your browser tab. Concretely:

• The file you pick is read by JavaScript in your own browser, as a local File object. It is not transmitted to Audio Trimmer servers, to any cloud worker, or to any third party.
• The actual processing runs via WebAssembly (a copy of FFmpeg compiled for the browser, loaded from a public CDN) and the browser's own audio decoder (the Web Audio API). These components run on your CPU, in your tab.
• The output file (a trimmed clip, an extracted soundtrack, a muted video) is generated in your browser's memory and handed to you as a download. It exists only on your machine.
• When you close or reload the tab, everything related to your file is gone from memory. There is no server-side copy, because there was never a server involved.

We designed it this way deliberately: private material — unreleased music, confidential interviews, client voice-overs, family videos — never needs to leave your custody, so there is nothing for us to leak, store, or delete later. The safest upload policy is not having one.

The stem-separation Windows app

The vocal and background-music separation engine cannot yet run reliably inside a browser, so those pages recommend a free, open-source Windows application (Ultimate Vocal Remover, MIT licence) that performs the separation locally on your PC. When you download that application:

• The installer downloads directly: by default the copy shipped with this site, and only if that copy is unavailable does your browser fetch the file from the project's official GitHub release. It is a plain file download — no API is queried, nothing about you is sent along, and Audio Trimmer stores nothing from it.
• The application itself runs offline on your machine. Your audio files are processed by your own CPU or GPU and are not uploaded by that software as part of separation. Its behaviour is governed by its own project and licence, which we encourage you to read.

We recommend the application because it is genuinely free, genuinely local and genuinely open source — the same principles this site is built on — not because we operate it.

Technical data the site itself touches

While your media never travels, a website is never entirely data-free. Here is the complete inventory:

• Static hosting logs. The pages, scripts and styles are served from static hosting. Like every website, the hosting provider records standard request logs (IP address, requested URL, timestamp, user agent) for security and abuse prevention. We do not use these logs to profile you, and we cannot tie them to any media file, because no media file ever reaches the server.
• Content delivery network. The in-browser processing engine (FFmpeg compiled to WebAssembly) is loaded from a public CDN, jsDelivr. Your browser requests those files directly from the CDN, which involves the CDN seeing your IP address and the requested file name — the same as loading any JavaScript library from any site. No information about your media is included in those requests.
• Local preferences. A theme preference (dark or light) may be stored in your browser's local storage. The resolved download link is cached in your browser's session storage for a few hours so the installer button does not re-check it on every page. Both live only in your browser and are never sent anywhere.
• No analytics by default. The site does not run its own analytics, does not set advertising cookies, and does not embed social widgets. If privacy-friendly, aggregate-only counting is ever added, this page will be updated first.

What we do not do

For the avoidance of doubt, in plain language:

• We do not upload, receive, store, back up, or process your audio or video files. There is no media database, no job queue, no temporary storage bucket.
• We do not use your files to train machine-learning models — a meaningless promise for files we never receive, but worth stating explicitly.
• We do not sell, rent, or share personal data, because we do not collect any personal data.
• We do not require accounts, emails, or payment details, and there is nothing to delete when you stop using the site — closing the tab is the full uninstall.

Children and legal uses

The service is intended for a general audience and is not directed at children under 13. The tools are designed for material you own or are licensed to process — your own recordings, licensed stock media, or content where your use qualifies as fair use or fair dealing under applicable law. Processing a file does not change its copyright, and this policy is not a licence to infringe someone else's.

Changes to this policy

If the processing model ever changes — for example, if an optional cloud feature were added — this page will be updated and re-dated before the change takes effect, and the change will be described in plain language rather than buried. The current version is dated above; previous versions are not retained, because the previous promises were kept and retired with the behaviour they described.

Contact

Audio Trimmer does not publish a support email address. Questions about privacy can be raised in the project's public issue tracker, which is linked from the contact page. Because we hold no personal data and no media files, there are no data subject requests to fulfil — but if you believe something on this page is inaccurate, please tell us there and it will be corrected.