Privacy Policy
Effective date: October 12, 2026 · Version 2026-10-12
Langle ("Langle", "we", "us") is a Korean-learning app for learners around the world, operated by Seung-hyun Lee (이승현). This policy explains what personal information we process when you use the Langle app and its web pages, why, for how long, who helps us, and the rights you have. It is written to meet the Personal Information Protection Act of Korea (PIPA) and, for users in the EU/EEA and the UK, the GDPR.
1. Who is responsible
- Controller and Chief Privacy Officer: Seung-hyun Lee (이승현)
- Contact: vioin8449@gmail.com
2. What we collect and why
We collect only what we need to run the app. We do not collect your real name, phone number, address, contacts, location, or advertising identifiers, and we do not sell personal information or use it for targeted advertising.
Account (needed to provide the service)
- Email address, password (stored only as a one-way hash by our authentication provider), nickname, optional profile picture, sign-in sessions.
- Birth year, used only to confirm you are at least 16 (see section 9).
- Display language and time zone.
- Security data: failed sign-in count and temporary lock time, one-time verification codes for sign-up, password reset and email change.
Consent records (to prove what you agreed to)
- Which document or option (Terms, Privacy, age confirmation, optional marketing and other options), whether you agreed, the document version, and the time.
Learning settings and progress (needed to provide the service)
- Native language, Korean level, learning reasons, interests, daily goal, reminder time, subtitle, speech-level and audio-speed preferences, onboarding status.
- Placement and Hangul test answers and results, your study cards and the review schedule, review history and study time, daily routines and their step results, sentences you build, streaks, saved video clips and which clips you have been shown, notices you have read.
- Daily usage counters (how many routines, speaking checks and conversations you used each day) to apply free limits.
Speaking practice
- When you speak, your phone's built-in speech recognition turns your voice into text. Langle does not receive or store your voice recording. We receive the recognized text, the sentence you were practicing and the length of the attempt, and we store the score and the syllable-by-syllable result.
- The "Keep my recordings" option in Settings → Privacy currently has no effect: because recognition happens on your phone, there is no recording for us to keep.
AI conversation (iPhone)
- On supported iPhones, the AI conversation partner runs on your device using Apple's on-device model (Apple Foundation Models). Your conversation is not sent to any AI company.
- We store the text of each turn (yours and the AI's) on our server so you can see your history and report. Before storing, we automatically replace things that look like personal information (phone numbers, email addresses, ID and card numbers) with "[개인정보]"; links are blocked. Please do not share personal information in conversations.
- We also store conversation metadata: the situation, mission result, turn count, hints used and whether you typed or spoke.
Support and reports
- Messages you send through Send feedback, any screenshots you attach, our replies, and technical context sent with the message (app version and build, platform, OS version, device model, language).
- Content reports (for example a wrong translation), with your optional note.
Device
- An app installation ID, platform, app version and build number, OS version, device model, language, time zone, notification permission status, and last-seen time. Used to keep the app working on your device and for support.
Technical logs
- When the app or web pages talk to our servers, our hosting providers automatically record request logs that include your IP address, the time, the requested address and errors. These are used for security and troubleshooting.
3. Speech, text-to-speech and on-device processing
- Speech recognition uses your phone's built-in engine (on iPhone, Apple's Speech framework; on Android, the system speech recognizer). Depending on your device and settings, Apple or Google may process the audio on their own servers to recognize it. That processing is done by Apple or Google under their own privacy terms; Langle does not receive the audio.
- Read-aloud (text-to-speech) uses your phone's built-in voices.
- Microphone and speech-recognition access are requested only when you first use a speaking feature and can be turned off at any time in your phone's settings.
4. Legal bases (EU/EEA and UK users)
- Performance of our contract with you: account, learning features, speaking checks, conversation history, support.
- Legal obligation: age confirmation, consent records, handling of your rights requests.
- Legitimate interests: security logs, preventing abuse, fixing bugs, handling content reports.
- Consent: optional marketing messages and any other optional item you turn on. You can withdraw consent at any time.
5. How long we keep it
- Account, learning data, conversation turns, speaking results, devices and consent records: for as long as you have an account. When you delete your account they are deleted (see section 7).
- Verification codes and sign-up sessions: until they expire or are used (minutes to hours). Request replay records: 24 hours.
- Support messages and content reports: when you delete your account, the link to your account is removed, and the message is kept without it for up to 3 years after it was resolved, so we can handle disputes and repeat issues.
- Data export files: deleted 7 days after they are ready.
- Server logs: only for the short period our hosting providers keep them.
- If a law requires us to keep something longer, we keep it separately for that period only.
6. Sharing and service providers (processing on our behalf and transfers abroad)
We do not sell or rent personal information and do not provide it to third parties for their own purposes, except where the law requires it (for example a valid court order).
We use the following service providers to run Langle. They process data only on our instructions.
- Supabase, Inc. (United States) — authentication, database, file storage and server functions. Data items: all of the data in section 2. Data is stored in the Seoul region (South Korea, ap-northeast-2). Supabase staff and sub-processors outside Korea may access it for operations and support. Transferred over the network (encrypted) whenever you use the app; kept for the periods in section 5.
- Vercel Inc. (United States) — hosts our web pages (this policy, support and password-reset pages). Data items: IP address and request logs when you visit them; the password-reset page passes your reset code and new password directly to our server over an encrypted connection.
- Email delivery provider (SMTP) — sends sign-up codes, password-reset and email-change emails. Data items: your email address and the email content. Kept according to the provider's retention.
- Apple / Google — app distribution, and, where your phone's settings use them, speech recognition (section 3). These act under their own terms.
- YouTube (Google LLC, United States) — some lessons may show short clips from public YouTube videos in an embedded player. When a clip plays, YouTube may collect data under Google's Privacy Policy.
Because some of these companies are based outside Korea, using Langle involves transfer of personal information abroad (mainly to the United States), at the time you use the service, over encrypted connections. If you do not agree to this transfer, you can decline by not using the service or by deleting your account; the service cannot be provided without these providers. For EU/EEA and UK users, transfers rely on the providers' standard contractual clauses or equivalent safeguards.
Not used: the app contains no crash-reporting or product-analytics tools, and no subscription or payment service. Langle does not currently send push notifications or sell subscriptions. If we turn on any of these, we will update this policy first and ask for consent where required.
7. Deleting your data
- Delete your account in the app: Settings → Delete account. After you confirm with your password, your account enters a 30-day grace period during which you can sign in and cancel the deletion. After 30 days, your account and the data linked to it are permanently deleted, except the support records described in section 5.
- Deleting your account does not cancel an App Store or Google Play subscription; manage subscriptions in the store.
- You can also ask us by email to delete your account.
- Deleted electronic data is erased so that it cannot be restored. We do not keep paper records.
8. Your rights
You can, at any time:
- see and correct your profile and learning settings in the app;
- download a copy of your data (profile, learning history, cards, conversations and consent records): Settings → Privacy → Download my data. We prepare the file and email a download link to your account email address, normally within 72 hours; the link works for 7 days and the file is then deleted. You can request a copy once every 7 days;
- withdraw optional consents in Settings;
- ask us to access, correct, delete, restrict or stop processing your personal information, or to transfer it, by emailing vioin8449@gmail.com. We reply within 10 days (and within one month for GDPR requests). We may need to confirm it is you;
- complain to a supervisory authority. In Korea: Personal Information Infringement Report Center (privacy.kisa.or.kr, ☎ 118), Personal Information Dispute Mediation Committee (www.kopico.go.kr, ☎ 1833-6972), Supreme Prosecutors' Office cyber crime (☎ 1301), Korean National Police Agency cyber bureau (ecrm.police.go.kr, ☎ 182). In the EU/EEA or UK: your local data protection authority.
You may exercise your rights through a representative with written authorization.
9. Children
Langle is for people aged 16 and over. At sign-up we ask for your birth year and do not create an account unless you are clearly at least 16. If we learn that a user is under 16, we will suspend and delete the account. If you believe a child has signed up, contact us.
10. How we protect your data
- All connections between the app, web pages and our servers are encrypted (HTTPS/TLS). Data is encrypted at rest by our hosting provider.
- Passwords are stored only as one-way hashes.
- Database tables are locked down so that apps cannot read them directly; only our server code can, and it limits every request to your own data.
- Access to production systems and keys is limited to the operator.
- Repeated failed sign-ins temporarily lock the account.
- Conversation text is automatically scanned and personal details are masked before it is stored.
11. Cookies and tracking
The app does not use advertising identifiers and does not track you across other companies' apps or websites. Our web pages do not set cookies, except that YouTube's embedded player (if shown in the app) may use its own.
12. Changes to this policy
When we change this policy we publish the new version with its effective date in the app and at https://langle-links.vercel.app/privacy, at least 7 days before it takes effect (30 days for important changes). Where the law requires, we ask for your consent again in the app.
- Version 2026-10-12, effective October 12, 2026.