Privacy

Last updated: 11 August 2026

Your audio never leaves your computer. BPM Lock has no upload endpoint, no file storage and no server-side processing. Decoding, beat detection, time-stretching and encoding all run inside your browser tab.

What happens to the files you open

When you choose a track, your browser reads it from your own disk into the memory of the page. It is analysed and rendered there, and the corrected file is written straight back to your downloads folder. None of it is transmitted to us or to anyone else at any point. Close the tab and the audio is gone from memory.

Everything online wants to watch you do it. We went the other way. Privacy is a human right, and you should be able to run a track through BPM Lock without wondering where it went or who else has a copy. You do not have to take our word for it, either: open your browser's developer tools, switch to the Network tab, and watch that nothing goes out while a track is processed. You will see a couple of small requests when the page first loads, which are the page-view and page-speed reporting described below, and nothing at all after that.

Cookies and tracking

This site sets no cookies and uses no advertising or cross-site trackers. There is no account system, so we hold no usernames, passwords or email addresses from use of the tool.

We do measure two things, both through Vercel and both cookieless and first party. Web Analytics counts page views: which page was opened, roughly which country it was opened from, and what kind of device it was. Speed Insights records how quickly the page itself loaded and responded, which is how we find out the site is slow for someone before they give up on it. Neither can follow you anywhere else on the web.

Your rights

Because we do not collect personal data through the tool, there is generally nothing for us to access, correct or delete. If you have contacted us by email and want that correspondence removed, write to the address below and we will delete it.

Contact and support

Questions, bugs, or a track that BPM Lock handles badly: bpmlockapp@gmail.com. Just shoot us an email and we will get back to you as soon as we can.

Bug reports are much easier to act on with the genre and rough tempo of the track, your browser and operating system, and what you expected versus what you heard. Please do not email audio files. We cannot accept them, and you should not need to send them.