Privacy Policy
Last updated: 10 June 2026
This policy explains what data MixSleuth ("we", "us") processes when you use the MixSleuth Mac app and the mixsleuth.com website, and your rights under applicable data protection law. MixSleuth is the trading name of an independent sole trader, who is the data controller; you can contact us at [email protected], and we'll provide full registered details on request.
1. The app analyses your mixes on your device
The core of MixSleuth — splitting a recorded DJ mix into a tracklist by matching it against your own music library — runs entirely on your Mac. Your mix files and your library are read locally and are not uploaded to us or to any server. The fingerprints and analysis caches the app creates are stored locally in your app support folder. If you never use online identification, no audio or fingerprint data leaves your computer.
2. Online track identification
When you choose to identify tracks online (for tracks that aren't in your own library), the app sends short audio clips — typically a few seconds each — to a music recognition service. We use:
- Standard (single-source) identification — your Mac computes a compact audio signature on-device and sends that signature (not the audio itself) to Apple's music-recognition service to look up a match. This is governed by Apple's Privacy Policy.
- Deep (multi-source) identification — short audio clips are sent, via our own relay server, to a specialist third-party recognition catalogue. We operate the relay only to protect access credentials and apply fair-use limits; we do not retain your clips on it beyond what is needed to complete the request. The provider's handling is governed by their terms.
Only the clips needed for identification are sent — never your entire mix file. The result we receive back is track metadata (artist, title and similar), which is shown to you and stored locally with your session.
3. Anonymous app usage statistics
To understand which features get used and how well track identification performs in the real world, the app sends us small, anonymous usage events — for example "a scan of a 60-minute mix ran; the standard pass made 120 lookups and found 18 tracks; the deep pass made 12", or "a tracklist was exported as CUE".
These events contain counts, durations and feature names only. They never include audio, fingerprints, file names or paths, track titles or artists, the contents of your music library, or any account, device or install identifier — there is nothing in them that lets us tie an event to you, your mixes or your music. Because the data is anonymous, it is not personal data; we still tell you about it because we think you should know exactly what the app sends.
Each event also carries a simple build-origin label — development build, one of our own test machines, or customer build — so we can exclude our own testing from the statistics. On our machines this label is set by comparing a one-way hash of the machine id against a built-in list of our own computers; the comparison happens on the device, the hash is never transmitted, and on your machine the label simply says "customer build". It carries no information about you or your device.
You can switch this off at any time in the app's Preferences → Privacy ("Share anonymous usage statistics"); the app works identically with it off.
4. Purchases and payments
We never see or store your card details. Payments are handled by our payment providers, who act as merchant of record:
- On the Mac App Store, Apple processes your purchase and subscription under its own terms.
- For direct purchases, Polar — a third-party merchant of record — processes the payment, handles applicable taxes and receipts, and provides your licence. They share with us only what we need to deliver and support your purchase (for example your email and order reference).
5. The website
mixsleuth.com is a static site and its free browser tools (such as the Track Marker and the Rekordbox → Mixcloud converter) run entirely in your browser — the files you load into them are not uploaded. We keep any website analytics minimal and privacy-respecting, and we do not use advertising trackers.
6. Legal bases (GDPR)
- Performance of a contract — to provide the app, process purchases, and deliver support.
- Legitimate interests — to operate the relay service securely, prevent abuse, and improve the product.
7. Your rights
Where data protection law such as the UK or EU GDPR applies to you, you have the right to access, correct, delete, restrict or port your personal data, to object to certain processing, and to withdraw any consent. To exercise any of these, email [email protected]. You can also complain to your data protection regulator — in the UK, the Information Commissioner's Office (ico.org.uk); in Hong Kong, the Office of the Privacy Commissioner for Personal Data (pcpd.org.hk).
8. Data retention
On-device data stays until you delete it or uninstall the app. Purchase and support records are kept as long as needed for the service and to meet legal/accounting obligations.
9. International transfers
Some providers (e.g. Apple and our music-recognition, payment and hosting providers) may process data internationally. Where they do, appropriate safeguards such as standard contractual clauses apply.
10. Children
MixSleuth is not directed at children under 16, and we do not knowingly collect their data.
11. Changes
We may update this policy as the product evolves. We'll change the "last updated" date above and, for material changes, give notice in the app or on this site.
12. Contact
Questions or requests: [email protected].