Privacy Policy
Music Library Doctor ("MLD", "the app") is built by an independent developer. This page explains exactly what data we collect, what we deliberately do not collect, and how you can opt out.
What we collect
When the app is running (unless you have opted out), a small number of anonymous events are sent to our own server:
- App version (e.g.
1.0.18) — to understand which versions need support. - Platform and architecture (macOS/Windows, arm64/x64) — to prioritize platform work.
- Licensed state — a simple true/false flag indicating whether a Pro license is active.
- Device identifier — a 16-character one-way hash derived from your machine's hardware ID. The hash itself cannot be reversed. That is not the same as being anonymous to us: where we already hold your email address — from a purchase, or because you gave it to us — our own admin panel matches the two and shows your address next to your events.
- Launch and license-change timestamps — when the app started, when a license was activated or deactivated.
On this website, a single landing_view event is recorded on page load, containing only the anonymous ID above and the path visited. If you arrive through one of our own campaign links it may also include that link's campaign tag (utm_*), and we record a coarse country worked out from your device's time-zone setting (e.g. "Europe/…"). No cookies, no referrer, no IP address — the time zone only places you in a broad region, never identifies you. If you arrive through a partner or affiliate link, that link's referral code is kept in your browser's local storage for up to 90 days so the partner who sent you is credited if you buy. The code identifies the partner, not you, and it is passed only to our payment provider (Lemon Squeezy) at checkout. Clearing your browser storage removes it.
What we DO NOT collect
- Your name, email address, or any other personal information.
- Your music files. Your audio never leaves your computer — not when the app scans, not when it repairs, not when something goes wrong.
- Your license key or any payment information.
- Your IP address — it is never written to our database.
- Session recordings, screenshots, keystrokes, or mouse movements.
- Third-party analytics cookies or trackers.
- Any data from third-party DJ software (Rekordbox, Serato, VirtualDJ) beyond what is strictly needed for the app to function locally on your machine.
When something goes wrong
When something in the app fails — it crashes, or an operation such as a download or a clean-up cannot finish — it sends us a diagnostic report so we can find the cause. This report never contains your music. What it does contain is the shape of your library as the app sees it: file and folder paths, the names of your playlists and crates, and a copy of the app's own database about your collection. We need it because most faults in this app are faults in how a library is arranged, and they cannot be reproduced without seeing that arrangement.
The report is labelled with your device identifier and, where we have it, the email address you gave us, so a report can be matched to the conversation it arrived with.
This data is never shared with anyone. It is not sold, not passed to advertisers, not handed to any third party, and not used for anything except fixing the fault that produced it. It is stored privately and read only by us.
How to opt out
There is no switch for this in the app, and we would rather say why than hide it: a fault report we only receive from people who remember to turn it on is a fault report we mostly do not receive, and the app stays broken for everyone else. Usage statistics and diagnostic reports are both always on.
If you would rather we did not receive them, write to us: we can stop the usage statistics for your installation. Diagnostic reports we do not switch off, for the reason above — they are sent only after something in the app has already failed, and a fault we cannot see is a fault that stays. The address is at the bottom of this page, and you do not have to give a reason.
On this website: to block the landing-view ping, use a standard tracker blocker (uBlock Origin, Brave Shields, etc.) or your browser's DNS-level blocking.
Where the data lives
- Our own infrastructure — events are stored in Firebase Firestore (operated by Google Cloud, EU region). We don't share them with any third-party analytics provider.
- Retention: unlimited — event records are kept indefinitely. No IP addresses are stored. Each record carries the device identifier above, and whether that identifier leads back to you depends on what else we hold: with an email address on file it does, without one it does not. If you hold a licence, each record also carries the email address you bought it with, so our admin panel can show whose activity it is.
- Lemon Squeezy — if you purchase a Pro license, Lemon Squeezy (the merchant of record) processes your payment and email. We receive only the aggregated sales data. Lemon Squeezy's privacy policy.
Your rights under GDPR / KVKK
A diagnostic report is sent only when something in the app has already failed, and it does carry personal data: the paths of your files and folders, which include your account name, and the email address you gave us if you gave one. You can ask us for a copy of what a report of yours contains, or ask us to delete it, and we will — write to the address below and you do not have to give a reason. Nothing in these reports is ever shared with a third party.
Children
The app is not directed at children under 13. We do not knowingly collect any data from them.
Changes to this policy
We may update this page. The "Last updated" date above always reflects the current version. Significant changes will be announced in the app's release notes.
Contact
For privacy questions, reach us via our community on Reddit or the in-app Help → Send Feedback & Get Updates panel.