Last updated: November 8, 2026
This privacy policy explains what information StemSplitter.app ("we", "us") collects when you use this website and its tools, how it is used, and the choices you have. The short version: your audio files never leave your device. We do not receive, store or see the songs you separate.
Privacy of your audio files
All tools on this site, including the stem splitter, vocal remover, drum remover and the other pages, process audio entirely on your device. When you choose or drop a file, the page reads it locally, decodes it, and runs the separation model on your own hardware using WebGPU or WebAssembly. The resulting stems are created in local memory and saved to your computer only when you click a download button. No part of your audio, its file name or its metadata is sent to our servers or to any third party. Closing or reloading the page discards everything that was in memory.
The AI model download
To run the separation, your browser downloads the AI model files (about 170 MB) and the ONNX Runtime engine from our own file server, models.stemsplitter.app, which is hosted on Cloudflare R2. If that server is unreachable, the same files are fetched from public mirrors instead: Hugging Face for the model and the jsDelivr content delivery network for the engine. These requests are ordinary file downloads, similar to loading an image; they do not include your audio. Like any web server, these providers can see your IP address and browser type when the files are requested, under their own privacy policies. The model is stored in your browser's cache storage so it does not need to be downloaded again. You can remove it at any time by clearing this site's data in your browser settings.
Information this privacy policy covers
Server logs
Our pages are served by Cloudflare. As with any website, Cloudflare processes technical request data such as IP address, browser user agent, requested page and time, to deliver the site and protect it against abuse. We do not use these logs to identify individual visitors.
Analytics
We may use Microsoft Clarity to understand how visitors use the site in aggregate, for example which pages are visited, where people click and where the layout causes problems. Clarity uses cookies or similar technologies and collects usage data such as clicks, scrolling and device information. It does not receive your audio. Microsoft's privacy statement describes how it handles this data.
Advertising
To keep the tools free we may show ads served by Google AdSense. Google and its partners may use cookies to show ads based on your previous visits to this and other websites. You can opt out of personalised advertising in Google's Ads Settings, or learn more at Google's page on how it uses information from sites that use its services. Ads run in separate frames and have no access to your files.
If you email us, we receive your email address and whatever you write. We use it only to answer you and do not add you to any mailing list.
Cookies, local storage and privacy
The tools themselves do not set cookies. The only thing they store is the AI model in your browser's Cache Storage, so it loads quickly next time. Analytics and advertising providers described above may set their own cookies. You can block or delete cookies in your browser settings; the separation tools keep working without them.
How we use information
- To deliver and secure the website.
- To understand which features are useful and fix problems.
- To show advertising that pays for running the site.
- To reply to messages you send us.
We do not sell personal information, and we do not build profiles of individual users. Privacy is the reason this policy is short: a tool that never receives your audio has very little to protect.
Your privacy rights
Depending on where you live, you may have rights to access, correct or delete personal data about you, or to object to certain processing. Because we hold almost no personal data, the most effective privacy controls are in your browser settings: clear site data, block cookies, or use your browser's privacy features. For any request about data we may hold, such as an email you sent, contact us through the address on the about page.
Children
This site is not directed at children under 13, and we do not knowingly collect personal information from them.
Changes to this privacy policy
If we change how the site handles data, for example by adding a new analytics or advertising provider, we will update this page and the date at the top. The core privacy promise of this policy will not change: the audio you separate is processed on your device and is never uploaded.
Contact
Questions about this privacy policy, or about privacy on StemSplitter.app in general, can be sent to the email address listed on our about page.