Can Your Journal App Be Subpoenaed?
A subpoena can only reach what a company holds. If a journal app has nothing to hand over, the request has nowhere to land.
Read articleEncrypted journal app
Mini Diarium is a private offline diary app for Windows, macOS, and Linux. AES-256-GCM encryption, local-first storage, no cloud, no telemetry. Just your words.
Looking specifically for an encrypted journal app? Start with the encrypted journal guide for the short version of how Mini Diarium handles privacy, storage, and ownership.
Curious how it stacks up? See the side-by-side comparison of Mini Diarium against Day One, Notion, and Obsidian.
Free & open source · MIT License · No account required
The backstory
Mini Diarium is a spiritual successor to Mini Diary by Samuel Meuli, a beautifully simple app that did exactly what a journal should do. Over the years its dependencies aged out and the project went unmaintained. A fork turned out to be impractical, so Mini Diarium was built from scratch, keeping the same philosophy while rebuilding the entire stack with Tauri 2, SolidJS, and Rust.
The result is lighter, faster, and more secure, with stronger encryption, key file authentication, richer import support, and a codebase built to last. It's the journal app I always wanted to use.
What makes it different
Most apps encrypt at the app level while leaving the door open at the infrastructure level: iCloud, Google Drive, or a sync service owns your data and can read it. Mini Diarium encrypts every entry with a random master key using AES-256-GCM before it ever touches disk. There is no cloud, no sync service, and no server to compromise.
You can also unlock your journal with a private key file, the same concept as SSH keys, instead of (or alongside) a password. Keep the file on a USB drive, in a password manager, or on a separate machine. Each auth method holds its own wrapped copy of the master key; adding or removing one never requires re-encrypting your entries.
From the blog
Static articles that explain encrypted journaling, private diary apps, and how local-first writing protects ownership.
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Read articlePlenty of apps call themselves secure. A journal app earns it by encrypting entries on disk, running fully offline, and holding no key it could hand over.
Read articleWhat's inside
A private diary app should not depend on a server. Every feature decision starts with the same question: does this need the network? The answer is always no.
Available in: English, French (Français), German (Deutsch), Hindi (हिन्दी), Italian (Italiano), Portuguese (Brazil) (Português (Brasil)), Spanish (Español).
Every entry is encrypted with AES-256-GCM before it touches disk. Plaintext never exists on your storage. The encryption key never leaves your machine.
Register an X25519 private key file as a second unlock method. Keep it on a USB drive, in your password manager, or anywhere you control. No app, no OTP, no phone required.
No network calls. No telemetry. No update pings. Mini Diarium has no HTTP client, so it literally cannot phone home. Your writing habit is yours alone.
Bold, italic, headings, lists. TipTap-powered rich text editor with full keyboard support, spellcheck, and auto-save. Write without thinking about saving.
Jump to any day with a click, or use keyboard shortcuts to step forward and back. The calendar highlights every day that has an entry at a glance.
Migrate from Mini Diary (JSON), Day One (JSON & TXT), and jrnl (JSON) without losing same-date entries. Bring your history, keep it encrypted.
Export everything as JSON or Markdown any time. Your data is never locked in. Use it in other apps, back it up yourself, or just have peace of mind.
Mini Diarium snapshots your encrypted database before anything risky happens to it, checks every copy it writes, and keeps tiered history going back a year. Your entries are safe even if things go wrong.
See your word count, writing streaks, most active days, and total entries, all calculated locally, all encrypted at rest. Track your habit without sharing it.
Under the hood
A random 256-bit master key is generated when you create the journal and never changes. Every entry is encrypted with AES-256-GCM using that key before it is written to SQLite. The master key itself is never stored in plaintext: each authentication method (password or key file) holds its own wrapped copy: password slots use Argon2id key derivation + AES-GCM wrapping; key file slots use X25519 ECIES (ephemeral DH + HKDF-SHA256 + AES-GCM).
Adding a new auth method is O(1): only the wrapped key is re-created, not your entries. The same is true for changing your password. The app has no HTTP client, no analytics package, and no telemetry. It cannot send your data anywhere, even if it wanted to.
At a glance
Short answers for humans and machines: what Mini Diarium is, how it protects data, and what platforms it supports. For the category overview, read the encrypted journal guide.
Offline-only
Yes. No network calls, no telemetry.
Encryption
AES-256-GCM for entries at rest.
Storage
Local encrypted SQLite on your device.
Platforms
Desktop: Windows, macOS, Linux.
License
MIT, source available on GitHub.
Import/Export
Import Mini Diary/Day One/jrnl. Export JSON/Markdown.
Common questions
Mini Diarium is a private offline journal app for Windows, macOS, and Linux. It stores entries locally and encrypts them before they are written to disk.
Yes. The app does not send entries to cloud services and does not include telemetry. See the privacy policy.
Each entry is encrypted with AES-256-GCM before it is written to disk. See the security model for details.
Mini Diarium supports Windows 10 (1809) and later, macOS 10.15 Catalina and later, and Linux (Ubuntu 20.04+, Fedora 36+, Arch, or equivalent). Builds for all three are published from the GitHub releases page.
Yes. Supported imports are Mini Diary JSON, Day One JSON/TXT, and jrnl JSON. Exports are available in JSON and Markdown so your data is never locked in.
Not currently. Mini Diarium is a desktop app for Windows, macOS, and Linux. A mobile version is in our long-term vision if there is enough demand, but it is a significant development and maintenance effort. We are currently focused on keeping the desktop experience at the highest quality standards.
Available on
All releases are built via GitHub Actions and published with SHA-256 checksums. View all releases →
Requires Windows 10 (1809) or later, 64-bit.
Get it from the Microsoft Store for the easiest install: the Store signs the package and keeps it updated, so there is no SmartScreen warning. A Store install keeps its journals in its own data directory, separate from a direct-download install.
Prefer a direct download? Grab the .msi or .exe NSIS installer, no
admin rights required. These builds are unsigned, so Windows SmartScreen may show a warning on
first launch. Click "More info" then "Run anyway."
Mini Diarium is open source and builds are reproducible from source.
Requires macOS 10.15 Catalina or later. Universal binary, runs natively on Intel and Apple Silicon.
Download the .dmg and drag to Applications.
Gatekeeper may block it on first launch. Run once in Terminal:
xattr -cr "/Applications/Mini Diarium.app"
then launch normally. One-time step, no risk.
Requires Ubuntu 20.04+, Fedora 36+, Arch, or equivalent
(glibc 2.31+, WebKitGTK 4.1).
Download the .AppImage or .deb package.
Verify the SHA-256 checksum against checksums-linux.txt from the release before installing.
No code signing; transparency is the guarantee.
Release freshness
Current stable release: v0.6.6.
For the newest installers and checksums, use the GitHub releases page.
Support the project
Mini Diarium is MIT-licensed and free, with no ads, no telemetry, and no features held back behind a paywall. Donations cover running costs and the time to keep building, testing, and shipping it.
The author
Follow the project
Stay in the loop
Mini Diarium is open source. Watch the repo for releases, star it to show support, or follow along on social media.
Product Hunt profile coming soon.