Privacy Policy

Last updated: 17 September 2026 · Applies to the Key Detector Chrome extension and to keydetector.site

Key Detector analyses audio on your device. Your audio, your files and the pages you visit are never uploaded to us, and there is no account to create.

The short version. We receive three things: anonymous usage counts from the extension (which you can switch off), your email address if you buy Pro or start the free trial, and your email address if you subscribe to the newsletter. Nothing else.

1. Audio and files

Detection runs entirely inside your browser. Tab audio, microphone input and the files you open are processed locally and are never transmitted, stored or shared. The web analyser at keydetector.site works the same way: your files stay in the browser tab.

2. Anonymous usage data

From version 2.0 the extension sends anonymous counts to our own server (a Cloudflare Worker) so we can see which features are used and where the product fails. Each batch carries a random identifier generated on your device, which is not linked to your email or to any account.

We do send	We never send
Feature used (a detection finished, chords opened, chart printed) Analysis length in seconds and confidence level (low / medium / high) Whether a tempo was found, and how many chords were recognised Extension version, interface language, operating system Whether the licence is Pro or free	Audio, of any kind Page addresses, video titles or file names The detected key, mode or tempo Your email address Your IP address, which our server does not store

You can turn this off at any time in Settings → Help improve Key Detector. When it is off, nothing is sent and anything pending is discarded. These counts are deleted automatically after 180 days.

3. Your email address

If you start the 14-day free trial or buy Pro Lifetime, your email address is processed by ExtensionPay and Stripe to create and restore your licence, and by Stripe to take the payment. We never see your card details. If you subscribe to the optional email guide, your address is processed by Brevo with double opt-in, and every message has an unsubscribe link.

4. Stored on your device

Your analysis history, your preferences, your beta ratings and your licence status are kept in Chrome's local storage on your computer. Uninstalling the extension removes them.

5. Permissions the extension asks for

Tab capture — to analyse the audio of the tab you choose, while you ask for it.
Access to the current tab and scripting on YouTube — for Studio (transposition and speed) and for showing chords over the video.
Storage — for the preferences and history described above.
Side panel — for the Pro panel that stays open while you browse.

The extension does not read the content of the pages you visit and does not track your browsing.

6. Children

Key Detector is a tool for musicians and is not directed at children under 13. We do not knowingly collect data from them.

7. Your choices

Switch the anonymous counts off in Settings.
Ask us to delete any data associated with your purchase or newsletter subscription.
Uninstall the extension, which removes everything stored on your device.

8. Changes

If this policy changes in a way that affects what we collect, the date at the top changes and the change is described in the extension's release notes.

9. Contact

Questions about this policy or a deletion request: davidsocreative@gmail.com.