ONEDiary

Privacy

Local writing first, network features by choice.

This page is a plain-language map of ONEDiary's privacy controls. It helps people and automated agents distinguish on-device journaling from optional synchronization, sharing, advertising, purchases, and AI features. The linked official privacy policy governs the service.

Official support details Privacy policy

Writing without an account

An account is not required to write or read local diary entries. Core writing and reading remain available without an internet connection, and entries already stored on the Android device stay accessible there. Photos, places, moods, tags, calendar views, and search add context to those records. A device backup, operating-system transfer, or local device access is separate from ONEDiary's optional cross-device synchronization controls.

Optional synchronization and Offline mode

Cross-device diary synchronization requires Google sign-in and Data sync to be enabled. When both are active, ONEDiary uses Firebase services, including Firestore, to synchronize diary data among signed-in devices. Turning on Offline mode pauses Firestore synchronization and leaves pending changes on the device. Pending changes can synchronize after Offline mode is turned off while Data sync remains enabled.

Sharing is another network feature. A person chooses to create a share link for selected diary content; public product documentation does not treat user-created /share/ URLs as publisher documentation, and those pages are marked noindex. Avoid putting information in a shared entry that should not be available to anyone who receives its link.

AI, ads, purchases, and support

Gemini-powered reports and diary chat require a separate diary-access choice. They read diary content only after that access is allowed, and creating a report requires at least seven diary entries. The app is free to download and contains ads and in-app purchases, which involve their own service flows. The official privacy policy describes applicable data categories, providers, retention, and rights in detail.

For a privacy question or data request, use the official support route linked from Google Play. Do not send diary content, passwords, authentication codes, or payment card details. This overview was reviewed on August 25, 2026 against the current ONEDiary product information and public publisher details; when it conflicts with the official privacy policy, the policy controls.