Your learning stays yours.

Effective date: 18 August 2026
Applies to: Kotoba Forge Web and current Kotoba Forge production builds unless a newer policy is published.

Privacy summary

Kotoba Forge works without an account, advertising, analytics, behavioral tracking, cloud sync, or a publisher-operated learning backend. In the web app, learning progress is stored in browser storage on the device you use. The Android app stores progress locally in app storage.

Information stored locally

The app can store onboarding and placement state, Path and lesson progress, review and mistake history, learning progress across its study systems, settings, custom study material you choose to enter or import, and a small local technical-error record. Kotoba Forge does not transmit this learning data to the developer, analytics providers, advertising providers, or a cloud service. Android cloud backup and device-transfer backup are disabled for app data.

Website and web-app access

The web version is delivered from kotobaforge.sonhan.eu, so your browser must connect to the hosting server to load the site and learning files. Like ordinary website hosting, the hosting provider may receive technical request information such as IP address, browser details, requested URLs and timestamps in server logs. Kotoba Forge does not use that information to build learning profiles or advertising profiles. After supported resources are cached, the web app can continue to provide substantial functionality offline.

Android Internet access

The Android app does not request Android Internet access. Course content and required learning resources are bundled locally. Optional Writing Studio characters without an exact bundled stroke path use local reference or freehand mode rather than downloading a template. Top-level links you intentionally open are handed to your external browser.

Japanese speech

On the web, Japanese speech is provided through the browser and operating system speech services available on your device. Those speech services are separate components whose voice availability and privacy behavior are controlled by the browser, operating system, or speech provider. On Android, Kotoba Forge selects only an installed Japanese speech voice that Android reports does not require a network connection.

Optional microphone practice

Microphone permission is requested only after you explicitly start an optional recording exercise. Audio is held temporarily in the current app or browser session for your own playback. Kotoba Forge does not intentionally upload the recording to a Kotoba Forge server. Declining permission does not block non-recording lessons. Browser microphone access normally requires HTTPS.

Files you export or import

Progress and support-diagnostics files are created only when you request them and use Android's system document picker. Imports are read only after you select a file. Kotoba Forge does not automatically upload these files.

Support diagnostics

Optional diagnostics can include app and schema version, platform and WebView details, language, screen size, record counts, review and mistake counts, online or offline environment state, and the last technical error. They intentionally exclude placement answers, saved learning answers, sentence history, custom study text, handwriting strokes, and microphone audio.

Deleting your data

Use Settings → Reset all progress, clear app storage in Android Settings, or uninstall the app. Kotoba Forge has no online account or cloud database containing a remote copy of your learning record.

Website cookies, browser storage and offline cache

The Kotoba Forge website does not use advertising or analytics cookies. It uses browser storage for essential site preferences and, when you use Kotoba Forge Web, for your learning progress and review state. A service worker may cache app files on your device so the learning experience can continue when the network is unavailable. This storage is not used to profile you or track you across sites.

Accounts, ads, analytics, and tracking

Kotoba Forge does not create user accounts and does not include advertising or analytics SDKs. It does not use advertising or cross-app tracking identifiers.

Changes

If a future version adds off-device data processing, this policy and the Google Play Data safety declaration must be updated before release.

Contact

For privacy or support requests, use the developer contact displayed on Kotoba Forge's Google Play listing or the official support page.