Demirline
Support
Quick help for setup, API keys, captions, and hotkeys.
Quick start
- Install Demirline in Chrome.
- Click the extension icon → All settings.
- Choose a provider, paste your API key, set the target language.
- Open a YouTube video with captions and wait a moment for dual subtitles.
FAQ
Translation fails / API key error
Settings need a valid key and model for the selected provider. An OpenAI key will not work in the OpenRouter field. Check quota and billing on the provider dashboard.
No subtitles appear
The video needs at least one caption track (manual or auto). Refresh the page; YouTube UI changes can cause temporary issues. Try another source language track.
What do the hotkeys do?
Defaults: sentence repeat S; paragraph on any site Alt+T; word Alt+W; sentence Alt+S. Change them in Settings. Some sites may override the same shortcuts.
Is my API key safe?
The key is stored only in browser storage and AI requests run in the background service worker; the page cannot read the key. Still, never share it, and revoke it at the provider if leaked. See the privacy policy.
Which AI models can I use?
OpenAI, Anthropic, Google Gemini, and OpenRouter are supported. Models are listed in Settings; OpenRouter also routes many third-party models.
Contact us
If this page does not solve it, email us. Include when possible: Chrome version, error text, video URL (if any), and which provider you use.
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