Default mode
When Chrome's on-device Translator API is used, subtitle text stays in the browser. SubMate stores settings, subtitle sources, and translations locally so it can restore playback promptly. It does not operate a server that receives this data.
Optional cloud translation
Cloud translation is disabled unless you choose it and provide a provider API key. In that mode, subtitle text, language tags, and a small amount of preceding text are sent directly to the provider you chose. See AI translation for the exact boundaries.
What SubMate does not send
SubMate does not send cookies, authorization headers, signed media URLs, video, audio, title names, page URLs, or browsing data to cloud translation providers. It does not use analytics or a SubMate-operated proxy.
Permissions and control
Streaming hosts are limited to the services SubMate supports. Provider-host access is requested only when you select that provider and can be revoked in Chrome's extension settings. You can clear local caches or remove the extension at any time.
Policy changes
This summary must be reviewed with every release that changes data handling, permissions, or cloud behavior. The source code and release notes are public for audit.