Langosta Book Translator — Privacy Policy
Last updated: October 29, 2026
Who we are: Langosta Book Translator is run by Langosta Labs LLC, Utah, USA. Contact: hello@langostalabs.com.
What we collect
| What | Why |
|---|---|
| Your account: email, name and picture from Google sign-in, sign-in times | To sign you in and keep your library yours |
| Your books: photos of pages, the text read from them, text you type or paste, translations, highlights, notes, bookmarks, studies and questions you ask | That's the product: we store them so you can read and study them |
| Listen audio for your pages | So replaying a sentence is instant |
| Usage: pages and studies used this month, your plan, when you last opened the app and how many times | Monthly allowances and billing; spotting problems |
| Messages you send us (feedback, translation reports) | To answer and improve the product |
| Reading settings (theme, text size, tool) | Kept in your browser only, not on our servers |
We don't sell your data, show ads, or use your books to train AI models.
Who processes it for us
To read and translate your pages we send their content to:
- Google Cloud (Firebase): hosting, sign-in, database and file storage. Also Google Cloud Vision, which reads the text in your photos.
- Anthropic (Claude): translating your pages. Under Anthropic's API terms, what we send isn't used to train their models.
- OpenAI: explanations and studies, word lookups, and the safety check. Under OpenAI's API terms, what we send isn't used to train their models.
- Microsoft (Azure AI Speech): the spoken audio for Listen. Under Microsoft's terms for Azure AI services, what we send isn't used to train their models.
- Stripe: payments, once paid plans start. We never see your card number.
Shared translations
Translating the same sentence twice is wasteful, so when a sentence from a photographed page has been translated before, we reuse that translation. Each reader still pays their own page credit.
- What's shared is only a sentence and its translation. It doesn't say who it came from, which book it was in, or that anyone read it. Nobody can see your books, pages or library.
- Typed or pasted text is never shared, and neither is text you edit with "Edit text".
- Shared sentences can't be removed later. They aren't tied to you, so we can't find "your" sentences, even if you delete the book or your account.
Safety checks and who can see your content
Every page and question gets an automatic safety check before any AI work. If something is flagged, our admins can see a short excerpt of the flagged text, and they may open an account's library to review an issue or handle a support request. Every time an admin opens someone's account or books, it's recorded in an internal log.
How long we keep it
- Your books: until you delete them. Deleting a page or a book removes its photos, text, translations, studies and audio. Deleting a page keeps any highlights you made on it.
- Your account: until you delete it: account menu → Plan & billing → Delete my account. That ends any plan right away (no refund) and deletes your books, files and data across Langosta, and your sign-in. Payment records stay with Stripe as the law requires. You can also email hello@langostalabs.com.
- Safety-check records and the admin log: 12 months.
- Shared sentences: indefinitely, since they aren't personal (see above).
Your choices
You can view, edit or delete your books and pages at any time. You can ask for a copy of your data, or for your account to be deleted, at hello@langostalabs.com.
Children
The Book Translator isn't meant for children under 13. If you believe a child has an account, contact us and we'll delete it.
Changes
If we make a significant change to this policy, we'll tell you in the app before it takes effect.