Encryption Overview
This page explains, in plain language, how your data is handled. For the full legal text, see the Privacy Policy — if the two ever appear to disagree, the Privacy Policy is authoritative.
Your API key
Section titled “Your API key”- Free tier / guest mode: your API key is encrypted on your device with AES-256-GCM before it’s saved to local browser storage. The encryption key is derived locally and never leaves your device — we never see your key.
- Subscribers: your API key is end-to-end encrypted (JWE) in transit so it can sync to your other devices, and stored re-encrypted at rest on our servers. It is never written to disk or logs in plaintext, on either end.
Your translation text
Section titled “Your translation text”Whatever you translate — a selection, a page’s main content, or video subtitles — is sent directly from your browser to the LLM provider you configured, using your own API key. It never passes through or is stored on Flash Translate’s servers; we cannot see your translation content.
Your local logs
Section titled “Your local logs”Every translation request is logged locally in your browser — the model used, token counts, an estimated cost, and short previews of the source and translated text — so you can review your own usage. This log never leaves your device and is never synced, even for subscribers. You can clear it at any time from Settings → Logs.
Your translation text and local logs live only on your device — never uploaded to any server, never synced across devices.
Browser permissions
Section titled “Browser permissions”See the “Browser Permissions” section of the Privacy Policy for what each requested permission (storage, tabs, activeTab, identity, alarms, and the preset LLM provider domains) is used for.