Privacy

Lexio is a reading app for learning a language. This describes what it collects, what it sends elsewhere, and how to get rid of any of it.

The short version: reading needs no account and sends nothing anywhere. Everything beyond that is optional, and each optional thing is listed below with what it costs you in data.

Reading, with no account

The library ships with the app, already translated. Opening a text, tapping a word, saving it, and reviewing it later all happen inside your browser, and work with the network switched off.

What you read and save is held in your browser's own storage on the device you are using. It is not sent to us, and we cannot see it. Clearing your browser's data for this site erases it, and there is no copy anywhere else unless you have made one.

You can download everything as a file at any time from Settings, and restore it on another device, without an account.

Accounts, and what syncing sends

An account exists to carry your library between devices. It stores an email address and a password, which are handled by Neon Auth; the password is never visible to us.

When you are signed in, these are stored on our server so another device can read them: the texts you have added, the words you have saved, how well you know each one, when each is next due, and where you stopped reading in each text.

Texts from the bundled library are never sent — they already exist on every device, so only a reference to them travels. Texts you added yourself are sent in full, because there is nowhere else to get them from.

Signing out leaves everything on the device exactly where it is. It deletes nothing.

What we send to other companies, and when

Three services receive text or data, and each is only reached when you use the feature that needs it.

Anthropic receives a sentence when you ask the tutor to explain it, and receives imported text when you ask for it to be translated. Anthropic processes it to produce the answer. If you never use the tutor and never import a text, nothing reaches them.

Google Cloud Text-to-Speech receives a sentence when you ask to hear it and your device has no voice for that language. Your device's own voices are tried first, because they cost nothing and the sentence never leaves the machine; Google is the fallback that makes audio possible on a device that would otherwise be silent.

Stripe handles payment if you subscribe. See the section on payment below.

Our own infrastructure is hosted by Vercel, and the database by Neon. Both necessarily process what passes through them in order to run the service.

Payment

Card details are entered on Stripe's own checkout page and are never sent to us or stored by us. We could not see your card number if we wanted to.

What we store is a Stripe customer identifier and the date your subscription is paid through. That is the whole of it: no card, no billing address, no payment history on our side. Stripe holds those, under Stripe's privacy policy.

Stripe is the merchant of record for these payments, which means the transaction is between you and Stripe, and Stripe is responsible for tax on it.

Counting usage, and IP addresses

Translation, the tutor and read-aloud each cost money per use, so each is metered. Signed in, the meter is keyed to your account.

Signed out, there is no account to key it to, so it is keyed to your IP address — hashed with a secret key before it is written, and truncated. The stored value cannot be turned back into an address, and no raw address is ever written to the database. It exists to stop one caller from exhausting a shared allowance, and it is used for nothing else.

Cookies and analytics

One cookie, and only when you are signed in: the session cookie that keeps you signed in. There is no advertising cookie, no tracking pixel, and nothing shared with an ad network — we do not run ads and do not sell data.

We use Vercel Analytics to count page views. It does not use cookies and does not build a profile of you across sites.

Your language and reading preferences are stored in your browser so the app opens the way you left it.

Deleting things

Settings offers two different deletions, and neither can be undone.

Deleting your data removes the texts you added, the words you saved, how well you know each one, and your reading positions — from our server and from every device you sign in on. Your account stays, empty.

Deleting your account removes the account and everything with it. You are signed out and cannot sign back in.

One thing deletion does not do: it does not cancel a subscription. Stripe holds that, and it has to be cancelled through Stripe — the Settings page links to it, and warns you before you delete. If you close your account with a subscription running, the card keeps being charged until you cancel it. Write to us and we will help.

Download a backup first if you want to keep any of it.

How long things are kept

Your library and vocabulary are kept until you delete them or your account.

Usage counters are kept per day and per month and are not read after their window has passed.

The tutor keeps a cache of explanations for sentences from the bundled library, so the same sentence need not be paid for twice. Those are about the text, not about you: they carry no account identifier and are shared by everyone reading that sentence.

Children

Lexio is not directed at children under 13, and we do not knowingly collect anything from them. If you believe a child has created an account, write to us and we will remove it.

Changes, and how to reach us

If this changes in a way that affects what is collected or where it goes, the date at the top changes with it.

Questions, requests to see or delete what we hold, or anything else: support@lexio.page. A person reads it.