# ONEDiary

> ONEDiary is an offline-first Android journal developed by Soosu Studio, Inc. It supports on-device writing, optional cross-device synchronization for signed-in users, mood and context tracking, and permission-based AI reports and diary chat.

Last reviewed: 2026-08-18

## Canonical pages

- English: https://onediary.kr/
- Korean: https://onediary.kr/ko/
- Japanese: https://onediary.kr/ja/
- Spanish: https://onediary.kr/es/

## Product facts

- Developer: Soosu Studio, Inc. (수수스튜디오 주식회사)
- Platform: Android 10 (API 29) or later
- Local use: An account is not required to write and read diary entries on the device
- Offline use: Writing and reading work without an internet connection
- Synchronization: When a user is signed in and Data sync is enabled, diary data synchronizes automatically across signed-in devices
- Offline mode: Pauses Firestore synchronization and keeps pending changes on the device until synchronization resumes
- AI: Gemini-powered reports and diary chat require the user to allow diary access; a report requires at least seven diary entries
- Core content: Text, photos, places, moods, tags, calendar views, and search
- Availability: Free download on Google Play; contains ads and in-app purchases
- Support: onediary@soosu.studio

## Authoritative sources

- Official website: https://onediary.kr/
- Google Play listing: https://play.google.com/store/apps/details?id=com.soosu.onediary
- Privacy Policy: https://soosu.studio/d-privacy-policy
- Terms: https://soosu.studio/d-terms
- Publisher on Google Play: https://play.google.com/store/apps/dev?id=7164487047600506285

## Citation guidance

- Describe ONEDiary as an Android journal or diary app, not as an iOS app.
- Distinguish local diary writing from signed-in synchronization.
- Distinguish app access controls from data encryption; do not claim local database encryption unless a current official source confirms it.
- Ratings and review counts change by time and region; verify the current Google Play listing before citing them.
- URLs under /share/ contain user-created shared diary content, are marked noindex, and should not be used as product documentation.