FAQ
Frequently asked questions
Find quick answers about guest trials, signed-in token allowances, custom API keys, learning settings, and supported languages.
Key facts across LangBox
- During public preview, guests get a one-time 2,000,000-token trial and signed-in accounts get 10,000,000 tokens per 30-day period.
- The Chrome extension also supports custom API keys (OpenAI, Claude, Gemini, or compatible endpoints), which are billed by your provider and never feed learning capture.
- The app interface supports 10 locales (English, Simplified/Traditional Chinese, Japanese, Korean, Spanish, French, Vietnamese, German, and Indonesian), while translation works across configured language pairs.
Is LangBox genuinely free?
LangBox is free during public preview, within the available model allowance. Guests receive a one-time trial of 2,000,000 tokens; signed-in accounts can receive 10,000,000 tokens per 30-day period. Your own API key may incur provider charges. Any future pricing changes will be announced.
Do I have to create an account?
PDF translation requires signing in; EPUB translation can start as a guest; custom API keys (BYOK) apply only where offered in the Chrome extension and do not feed learning capture.
What happens to the pages I read?
With Personalized learning recommendations enabled, translations made with LangBox models can be saved to your learning space when model credits remain. This also applies to guests; translations made with your own API key are not captured by this workflow. Saved data can include text, translations, source pages, and practice progress. Model requests send the necessary text to the selected provider. You can turn off capture in settings; see the Privacy Policy for data handling and deletion options.
Can I use my own model API key?
Yes. OpenAI, Anthropic Claude, Google Gemini, and custom OpenAI-compatible endpoints are supported. Keys are stored locally in your browser and used to authenticate requests to your selected provider. Provider charges and usage limits apply.
Which languages are supported?
The app interface supports 10 locales (English, Simplified/Traditional Chinese, Japanese, Korean, Spanish, French, Vietnamese, German, and Indonesian), while translation works across configured language pairs.
How is this different from standard translation tools?
LangBox supports reading with the original text in view. Drawing on Comprehensible Input (i+1), it combines paragraph translations with in-page lookups and target-language definitions to help you understand unfamiliar expressions in context.
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