Privacy
Last updated: June 14, 2026 · Draft, not yet legally reviewed.
Short version: The free extension filters audio entirely in your browser — we never see it. Song titles are sent to public lyrics databases to find lyrics. The Pro tier needs your email for your account and billing. Audio sent to the AI backend is processed in memory and immediately discarded. We don't sell data, run third-party trackers, or train models on your audio.
1. Who we are
Karafilt is an open-source project that anyone can contribute to. The hosted service — your account, billing, and the AI backend — is operated by Betania.io, a business registered in Serbia, which is the controller of the personal data described below (“we”, “us”). Contact: privacy@karafilt.com.
2. The browser extension
This section is the privacy disclosure for the Karafilt browser extension (Chrome Web Store listing included).
- Free filtering is 100% local.The Spectral and Basic modes process the tab's audio inside your browser (WebAssembly). The audio never leaves your machine and we have no way to see it.
- Lyrics lookups.To find lyrics for what you're listening to, the extension sends the page's media title (e.g. a YouTube video title, artist/track) and the track duration to public lyrics services: lrclib.net, lyrics.ovh and genius.com. These requests are not linked to any account and contain no personal data; the services see them like any web request (including your IP address) under their own privacy policies.
- AI mode only:the tab's audio is streamed in short chunks to the processing server configured in the extension's settings — our hosted backend (Pro) or your own self-hosted server — processed in memory, returned, and discarded. Audio is never stored or used for anything else.
- Settings stay local.Your preferences (filter mode, mix, lyrics on/off, server address) are stored in your browser's extension storage, not on our servers.
- No analytics or trackers. The extension contains no analytics, advertising, or tracking code of any kind.
3. Data we collect (Pro accounts)
| Data | Why | Retention |
|---|---|---|
| Email address | Account sign-in, email verification, service notices | Until you delete your account |
| Paddle customer & subscription IDs | Linking your account to your subscription (Paddle is the merchant of record — we never see your card details) | Until account deletion; billing records kept by Paddle as required by law |
| Trial & usage metering (seconds of AI processing) | Enforcing the free trial and fair use of the AI backend | Until you delete your account |
| IP address + technical logs | Security and abuse prevention (standard logs of our hosting providers) | 30 days |
| Audio chunks sent to the AI backend | Vocal separation processing | Discarded immediately after processing — never stored |
We collect nothing from users of the Free tier — Spectral and Basic modes run entirely in your browser and need no account. Access to the AI backend uses short-lived signed tokens that are not stored anywhere.
4. Lawful basis (GDPR)
- Performance of contract — email, billing IDs, trial/usage metering. Required to provide the Pro service you signed up for.
- Legitimate interest — IP address and technical logs, limited to security, abuse prevention, and capacity planning.
- Legal obligation — billing and tax records (held by Paddle as merchant of record).
5. Who we share data with (subprocessors)
- Supabase — authentication and database (your account, trial and subscription status).
- Paddle — payments, as merchant of record. Paddle is the seller for Pro subscriptions and handles card data, VAT and invoices under its own terms; we never see your full card details.
- Vercel — website hosting.
- Our GPU compute provider — runs the AI vocal-separation models on the audio streamed in AI mode, which is processed in memory and discarded immediately.
Lyrics lookups from the extension (section 2) go directly from your browser to lrclib.net, lyrics.ovh and genius.com — they are independent services, not our subprocessors. We do not share data with advertisers, brokers, or other third parties.
6. International transfers
Some subprocessors above operate outside the EU/EEA (notably Supabase, Vercel and Paddle, in the United States). Where required, transfers are governed by the European Commission's Standard Contractual Clauses (SCCs). You can request a copy of the relevant clauses by emailing the address in section 1.
7. Your rights
Under GDPR (EU/UK) and the CCPA (California), you have the right to:
- Access the data we hold about you
- Correct inaccurate data
- Delete your data (right to be forgotten)
- Export your data (data portability)
- Restrict or object to processing
- Opt out of any future sale of personal information (we do not sell)
- Lodge a complaint with your local data protection authority
To exercise any of these, email privacy@karafilt.com. We respond within 30 days.
8. Cookies & analytics
We use only essential cookies — the session cookie that keeps you signed in. The browser extension uses this same session (never your password) to show your signed-in status in its panel and to request short-lived AI access tokens.
For aggregate page statistics this website uses Vercel Web Analytics, which is cookieless: it sets no cookies, stores no identifiers on your device, and does not track you across sites — we only see anonymous, aggregated counts. We do not use advertising, cross-site tracking, or cookie-based analytics (such as Google Analytics). If that ever changes, we'll show a consent banner first.
9. Children
Karafilt is not directed at children under 16. We do not knowingly collect data from anyone under that age. If you believe a child has provided us data, email us and we'll delete it.
10. Security
Data is encrypted in transit (TLS) and at rest. AI backend access uses short-lived signed tokens (minutes, not days) so there is no long-lived secret to leak. The backend itself holds no user database — it only verifies token signatures. No system is perfectly secure; if we ever experience a breach affecting your data, we'll notify you within 72 hours.
11. Changes
Material changes will be announced by email at least 30 days before they take effect. The last-updated date at the top of this page reflects the most recent revision.