Privacy policy
This policy explains how Demo Track Maker (https://ktkwmr.com/demotrackmaker/, "this site") handles information. In short: what you record and the songs you make stay on your device. Nothing is uploaded.
1. What you do in the app
The chords you type, the backing made from them, the sound you record with the microphone, the audio files you open, and the effects and mix are all processed only in your browser. None of them, and none of their names, are sent to our server or to anyone else. The microphone is used only while a track is armed for recording, after your browser asks for your permission. Exporting a project, a mixdown (WAV or MP3), a track, or MIDI only saves a file on your device. This site has no accounts, and we do not ask for your name, email address, or other personal information.
2. Data saved in your browser
The following data is saved in your browser's storage on your device. It is not sent to us.
- Your project: the project name, tempo, chords, backing settings and edits, effects, and the audio of each track (IndexedDB), so you can continue after reloading.
- The last mixdown format: WAV or MP3 and the MP3 quality (localStorage).
- App files: the pages and files of this site, and the MP3 encoder once it has been used, so the app works offline (Cache Storage).
To delete your project, use “Clear all” in the app. To delete everything, clear this site's data (site data and storage for ktkwmr.com) in your browser settings. If you want to keep a project, export it as a zip file first.
3. Information sent to external services
When you use this site, your browser sends information to the following services. This list also serves as the notice of external transmission required under Japan's Telecommunications Business Act.
| Service (operator) | When | Information sent | Purpose |
|---|---|---|---|
| Cloudflare (Cloudflare, Inc.) | Every page and file request | IP address, browser information (user agent), requested URL, date and time | Hosting this site, security, and access logs for operation |
| Cloudflare Web Analytics (Cloudflare, Inc.) | Every page view | IP address, browser information (user agent), the URL of the page, referrer, page load time. No cookies are used. | Counting page views (see "Analytics" below) |
| jsDelivr (a CDN run by Prospect One and its partners) | Only when you choose MP3 for a mixdown (until the encoder is saved in your browser) | IP address, browser information (user agent), the URL of the library file, the page that requested it (referrer), date and time. Your audio is not sent. | Downloading lamejs, the library that converts the mixdown to MP3 on your device |
4. Cookies and advertising
This site does not set cookies and does not show ads. If we add ads in the future, we will update this policy before they are shown.
5. Analytics
To see how many people use this site, we use Cloudflare Web Analytics. It counts page views without cookies and without identifying or tracking individual visitors across sites. We do not use Google Analytics.
6. Sharing with third parties
We do not collect personal information that identifies you, and we do not sell or provide it to third parties, except where required by law.
7. Contact
For questions about this policy, please open an issue on GitHub Issues. See about this site for the operator.
8. Changes to this policy
We may update this policy when the site changes, for example when we add or remove a service. The updated policy applies from the time it is posted on this page.
Effective: November 1, 2026