Privacy Policy — BPM & Key Finder

BPM & Key Finder Chrome Extension · Last updated: March 2026

Plain-English Summary This extension analyzes audio locally on your device to detect BPM and musical key. It does not collect, store, or transmit any data about you or your listening activity. Ever.

1. What Data Is Accessed

BPM & Key Finder uses the Chrome tabCapture permission to access the audio stream from the active browser tab when you explicitly click the extension icon and start analysis. This permission grants access to the real-time audio signal only — no video, no tab content, no page data, no URLs.

The audio stream is captured temporarily and processed in memory while analysis is running. It is discarded immediately when you stop the extension or close the tab.

2. How Audio Is Used

The captured audio signal is analyzed entirely on your device using the Web Audio API. The extension computes:

Tempo (BPM) via onset detection and beat tracking
Musical key via chromatic pitch class profiling (Krumhansl-Schmuckler algorithm)

All processing happens locally in your browser. The raw audio and the analysis results are never sent anywhere. No external servers, APIs, or services are contacted during or after analysis.

3. Data Storage

This extension does not store any data. It does not write to chrome.storage, localStorage, IndexedDB, or any other persistent storage mechanism. When you close the extension popup, all computed results are gone.

No cookies are set. No identifiers of any kind are created or retained.

4. Third Parties

This extension does not integrate with any third-party services, analytics platforms, advertising networks, or data brokers. It makes no outbound network requests of any kind.

5. Permissions Used

tabCapture — Required to access the audio stream from the active tab for real-time analysis. Used only while you are actively running the extension.
activeTab — Required to identify the currently focused tab so audio capture can be initiated. No tab content is read.

No other permissions are requested.

6. Children's Privacy

This extension is a general-purpose audio analysis tool. It does not collect any data from any user, including children. It is fully compliant with COPPA and similar regulations by virtue of collecting nothing at all.

7. Changes to This Policy

If this extension is ever updated in a way that changes its data practices, this privacy policy will be updated before the new version is published.

Given that the extension's core design is to perform all processing locally with no data collection, we do not anticipate material changes to this policy.

8. Contact

Questions about this privacy policy or the extension can be submitted through our contact page:
https://rysupaudio.com/pages/contact-us