Privacy
Updated 20 October 2026.
Signing in
You sign in with Google. Sign-in and the site's database run on Supabase. Supabase keeps what Google passes on at sign-in: your email address, name and a link to your photo. Of these the site uses only the email address: it shows it in the header and passes it to the payment provider when you pay.
What is kept about your reading
In your account: which book and page are open, which words you marked as known, how many times you saw each word and opened its translation, and how many words on a page to show in the other language. The reader uses this to decide which words to replace. A copy of your progress is kept in your browser so that reading does not wait for the network.
Your own books
An uploaded file (EPUB, FB2 or TXT) is kept until the book has been split into pages, then erased. The text of the pages is kept until you delete the book with the button on your shelf; its translations are deleted with it. Only you can see the book.
To translate a page, its text is sent to a DeepSeek language model: to DeepSeek itself, whose servers are in China, or through OpenRouter. The request carries no name, email address or account number. Translation runs on our own computer in the Netherlands, which reads the page text from the site's database.
Payment
The subscription is sold and paid for through Polar (polar.sh), which is the seller of record. Only Polar sees your card details. We give Polar your account number and email address and get back the status of your subscription, the end of the period you’ve paid for and Polar's customer and subscription numbers.
Cookies
gr-pair — your language pair, kept for a year. Supabase sign-in cookies — while you are signed in. There are no ads and no visitor counters on the site.
Who else processes data
Vercel — the site's server. Supabase — sign-in and database. Google — sign-in. DeepSeek (China) and OpenRouter — the text of pages. Polar — payment. We do not sell data or show ads.
Your rights
You can get a copy of your data, have it corrected, or have your account deleted with all its data. You delete your own books yourself; the rest is done on request. Send requests to support@gradualreader.app. You can complain to the Dutch data protection authority, the Autoriteit Persoonsgegevens.