Short answer: Notion is a collaborative, server-hosted workspace: entries live on Notion's servers, Notion holds the encryption keys, and Notion AI can process content when enabled. Mini Diarium is a single-user desktop app that encrypts each entry with AES-256-GCM before it touches disk, with no server, no account, and no AI processing.
Many people write journal entries in Notion because it is already open for everything else: task lists, project notes, and a daily template that took five minutes to set up. Nothing new to install, nothing new to learn. The workspace is free to start and syncs across every device automatically. Notion's community has written extensively about the daily-notes template pattern.
The concern that surfaces later is not about features. It is about where the words actually sit once they are typed: on Notion's servers, encrypted with a key Notion holds, and available as input to Notion AI if that feature is enabled on the workspace.
This post covers what that architecture means for journal writing specifically, and what changes when the same habit moves to a single-user, local-only app.
What Notion is built for
Notion is a collaborative workspace: pages, databases, and blocks that link together, built for teams to plan projects, maintain wikis, and share documents. A daily journal is one more page type layered onto that structure, usually built from a database template with a date property and a text field. It works, and the flexibility is real: the same workspace can hold a journal, a reading list, and a work tracker side by side.
That flexibility comes from a shared, server-hosted data model. Every page lives in Notion's backend so that it can be indexed for search, rendered identically across web and native apps, and shared with a workspace member in one click. None of that is a flaw. It is the design a team collaboration tool requires.
Where journal entries actually live
Notion encrypts data in transit with TLS and at rest with AES-256 on its servers, per its own security documentation. That protects entries from an attacker who intercepts network traffic or steals a disk from a data center. It does not make the workspace zero-knowledge. Notion holds the encryption keys, not the account holder, which means the service itself can decrypt content server-side. That access is what makes full-text search, page previews, and Notion AI possible: a workspace with content Notion could never read could not offer those features.
If Notion AI is turned on for a workspace, journal content becomes input the assistant can process on request, subject to Notion's own data-use terms. That is a deliberate trade for a feature many users want. It is a different trade than a journal app that never sends a network request in the first place.
What a single-user, offline design changes
A journal does not need multi-user sharing, real-time collaboration, or a server to make full-text search fast across a whole workspace. It needs one person's entries, organized by date, available even with no network connection, and unreadable to anyone without the password.
An app built for that narrower job can make different trade-offs than a team workspace. Encryption keys never leave the local machine. There is no server component for content to pass through, so there is no server-side decryption step to reason about, no infrastructure to trust, and no AI feature that could ever see a plaintext entry, because there is no channel for the entry to reach one.
Where Mini Diarium fits
Mini Diarium is a desktop journal for Windows, macOS, and Linux. It is free and released under the MIT license. Each entry is encrypted with AES-256-GCM before it is written to a local SQLite database, and the app has no HTTP client, no telemetry, and no account to create.
Authentication options include password, key-file, and passwordless unlock. The key-file option uses X25519 and behaves like an SSH private key: the file is the credential, with an optional password required alongside it. The app organizes entries by date, with a calendar view and support for multiple entries per day.
Exports cover JSON and Markdown, and imports work from Mini Diary, Day One, and jrnl formats. The comparison page has a full feature matrix against Day One, Notion, Obsidian, Standard Notes, and others.
Mini Diarium is not a workspace tool. There is no database view, no team sharing, no blocks or embeds, and no AI assistant. If a workspace that combines a journal with project tracking and team docs is what you actually need, Mini Diarium does not replace that. It is built for one person's private writing and nothing else, and it is currently desktop-only with no mobile apps.
The practical takeaway
Notion and Mini Diarium solve different problems. Notion is a shared workspace where server-side access to content is the mechanism behind search, sync, and AI features. Mini Diarium is a single-user journal where entries are encrypted with a key that never leaves the device, and there is no server for content to reach in the first place.
If a journal needs to live inside a broader team workspace, Notion's model is a reasonable fit and the trade-off is a known one. If the goal is a private journal where no server, no staff access, and no AI feature can ever see a plaintext entry, Mini Diarium is built around that constraint from the start. The encrypted diary explainer covers what encryption at rest actually guarantees compared to an account login, and the how to choose a private journal app post has the broader checklist. The comparison page has the full side-by-side feature breakdown.