Keylingual Privacy Policy

Last updated: October 18, 2026

Keylingual is a keyboard for people learning a language. This policy explains what the app does with your data. The short version: everything you type stays on your device, except the sentences you explicitly ask Keylingual to translate.

Who we are

Keylingual is made by Jiaying Xue, an independent developer in Toronto, Canada, who is responsible for the personal data described here. Contact: jiayingxue0@gmail.com.

What stays on your device

• Everything you type with the keyboard. To suggest and correct words, the keyboard reads the text just before the cursor in the field you are typing in. Word suggestions, next-word predictions, emoji and the translations shown above suggestions come from dictionaries bundled inside the app and are computed on your device.
• What the keyboard learns from your typing, such as the words you use often and which word usually follows which, so it can suggest your words first. You can erase it at any time with Clear learned words in Settings.
• The names from your contacts and the text replacements that iOS gives to keyboards. The keyboard uses them only so it does not autocorrect a friend's name and so your shortcuts expand. They are not saved by Keylingual and never leave your device.
• Your typing statistics and vocabulary record, and your settings (keyboard language, translation language, theme).
• Pronunciation playback, which uses the speech voices built into iOS.

Sentence translation

When you tap the translate button, Keylingual sends the current sentence to our translation service so it can be translated. This only happens when you tap the button, and it requires Allow Full Access in iOS Settings because iOS keyboards cannot use the network without it.

• What is sent: the text of the sentence you asked to translate, the target language, your keyboard language and your sign-in token. Nothing else from the screen.
• How it is processed: our server forwards the text to OpenAI's API, which produces the translation, and returns the result to you. We do not store the text. To apply the daily allowance we record, for each day, how many sentences and how many characters you translated, never the text itself. Under OpenAI's API terms, the text is not used to train OpenAI's models and is kept by OpenAI only for a limited period to detect abuse.

Your account

Whole-sentence translation needs a Keylingual account so we can give every person a fair daily allowance. You can sign in with a one-time code sent to your email (there is no password), with Sign in with Apple or with Google. We store:

• your email address (with Sign in with Apple this can be a private relay address) and the account ID that Apple or Google gives us when you sign in with them;
• when your account was created and whether you are on the free plan or Keylingual Pro;
• for each day, the number of sentences and characters you translated;
• if you subscribe to Keylingual Pro: the App Store transaction ID, which subscription you bought, when it expires and whether it was refunded. Apple sends us this so your Pro status stays up to date. Payment is handled entirely by Apple; we never see your payment details.

Services we use

• Vercel runs our server (United States).
• Supabase hosts the account database (United States).
• OpenAI translates the sentences you send (United States).
• Resend delivers the sign-in code emails.
• Apple provides Sign in with Apple and handles App Store purchases; Google provides Sign in with Google.

These providers process data only to provide their service to us. Your data may therefore be processed in the United States or other countries where they operate, which may have different data protection rules from where you live.

How long we keep data

• The text you translate is not kept by us.
• Your account data is kept until you delete your account.
• Like most servers, ours sees your IP address when your device connects. We use it only to deliver the request and to limit abuse; our server and database providers keep standard logs, which can include IP addresses, for a short time.

Deleting your account and your other rights

You can delete your account at any time in the app: Settings › Account › Delete account. This immediately deletes your email address, your daily counts and your subscription records; if you signed in with Apple, we also revoke Keylingual's access to your Apple ID. Deleting the account does not cancel an App Store subscription; cancel it in your Apple Account settings. You can also email us to delete your account.

Depending on where you live (for example in the European Union, the United Kingdom, California or Canada), you have the right to access the personal data we hold about you, to receive a copy of it, to have it corrected or deleted, and to object to or restrict how we use it. Email us and we will respond within 30 days. If you are in the EU or the UK, you can also complain to your local data protection authority; in Canada, to the Office of the Privacy Commissioner of Canada.

We use your data to provide the features you ask for (your account, sentence translation and Keylingual Pro) and, where needed, to prevent abuse and keep the daily allowance fair.

Full Access

If you do not turn on Full Access, the keyboard works fully offline: word suggestions, corrections, predictions, translations above suggestions, emoji, themes and statistics all work. Only whole-sentence translation needs Full Access, and even with Full Access the keyboard sends nothing until you tap the translate button.

Analytics and tracking

Keylingual contains no analytics SDKs, no advertising and no tracking. We do not sell or share your data. If you allow it in iOS Settings, Apple may share anonymous crash reports with us.

Changes

If we change this policy, we will update the date at the top of this page.

Open source

Keylingual is open source under the GPL-3.0 license. You can review exactly what the app does at github.com/Jiaying-Xue-0/keylingual.

Contact

Questions about privacy: jiayingxue0@gmail.com.