Legal
Privacy Policy
Last updated: July 22, 2026
The short version
- Your audio files never leave your device by default. Transcription runs inside your browser. The only exception is the optional Pro "Audio backup" feature, which is off by default and uploads your files only to your own private cloud storage when you explicitly enable it.
- If you have an account, your practice data (progress, transcribed text, saved sentences and words) syncs to our servers so you can continue on any device. You can turn this off anytime in your dashboard.
- We don't sell or share your data with advertisers. Ever.
What stays on your device
Audio files you upload are read, transcribed, and played entirely in your browser (WebGPU/WASM). The audio bytes are stored only in your browser's local storage (IndexedDB) so you can resume without re-processing. They are never transmitted to our servers; the only way audio leaves your device is the opt-in Pro Audio backup described below.
What we collect
Account information
When you sign up we store your name, email address, and (for email accounts) a hashed password. Google sign-in shares your name, email, and profile image with us.
Practice data (cloud sync, signed-in users)
To make your practice portable across devices, we sync: practice progress and scores, the transcribed text of files you process (sentence text and timestamps — not the audio), and your review notebook and word notebook. This data is private to your account, compressed, and never shared. You can disable sync per device in your dashboard; when disabled, everything stays in that browser only.
Audio backup (Pro, opt-in)
If you enable Audio backup in your dashboard, your uploaded audio files are stored in private cloud storage (Cloudflare R2) under a key only your account can access, so your own materials follow you across devices. Files transfer directly between your browser and the storage provider; they are never shared, published, deduplicated across users, or accessible to anyone but you. Turning the feature off stops new uploads; deleting a practice file deletes its backup.
Payments
Payments are processed by Stripe. We never see or store your card details; we store your subscription status and a Stripe customer reference.
Usage analytics
We use Google Analytics to understand aggregate feature usage (e.g., how many people try the demo). We don't send it your practice content or personal data beyond what GA collects by default.
Third-party services
Word lookups are sent through our server to Dictionary API or Datamuse, and word translations are sent through our server to a translation provider. These requests contain the word being looked up but not your account identity. Library audio may be fetched directly by your browser from its publisher (including VOA, archive.org, and NASA/megaphone CDNs). These requests are governed by those services' own policies. Your practice audio is never part of such requests.
Data retention & deletion
Synced practice data is kept while your account exists. Deleting your account removes all synced records. To delete your account or request an export, email contact@listenslice.com — we action requests within 30 days. Local data can be removed anytime by clearing your browser's site data.
Cookies
We use a session cookie to keep you signed in (NextAuth) and Google Analytics cookies for aggregate usage measurement. No advertising or cross-site tracking cookies.
Changes
If this policy changes materially we'll update this page and the date above. Questions: contact@listenslice.com.