Mini Diarium is now Fenmark. As announced earlier, we agreed with another app in the journaling space to move away from the old name. The app, this website, and the documentation now use the new name, and the site lives at fenmark.app.

Only the name changes. No action is needed on your part, and your journals and data are not affected in any way. Store listings and install commands will follow over the next releases. Read the announcement.

Daily releases published on GitHub

Encrypted journal app

An encrypted journal app
that stays yours.

Fenmark 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.

Download for Windows Download for macOS Download for Linux See how it works
Offline-only No sync service, no HTTP client, no telemetry.
Encrypted at rest AES-256-GCM protects each entry before it reaches disk.
Local-first storage Your journal lives in a local encrypted SQLite database.
Desktop support Windows, macOS, and Linux releases are available.

Looking specifically for an encrypted journal app? Start with the encrypted journal guide for the short version of how Fenmark handles privacy, storage, and ownership.

Curious how it stacks up? See the side-by-side comparison of Fenmark against Day One, Notion, and Obsidian.

Download Fenmark Get Fenmark from the Microsoft Store

Free & open source · MIT License · No account required

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The backstory

A successor to
Mini Diary

Fenmark 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 Fenmark 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

Encryption-first,
not encryption-bolted-on

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. Fenmark 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

Encrypted journals, offline writing, and product notes

Static articles that explain encrypted journaling, private diary apps, and how local-first writing protects ownership.

November 2, 2026

Mini Diarium Is Now Fenmark

The app has a new name. Your journals, settings, and backups do not move, and you do not need to do anything.

  • fenmark
  • mini diarium
  • announcement
  • encrypted journal
Read article

July 13, 2026

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.

  • encrypted journal
  • journal app privacy
  • data requests
  • local-first journaling
  • private diary app
Read article
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What's inside

Built for privacy.
Designed for daily use.

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: Chinese (Simplified) (简体中文), English, French (Français), German (Deutsch), Hindi (हिन्दी), Italian (Italiano), Portuguese (Brazil) (Português (Brasil)), Russian (Русский), Spanish (Español).

Your entries are yours forever

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.

Unlock like you SSH

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.

Truly offline

No network calls. No telemetry. No update pings. Fenmark has no HTTP client, so it literally cannot phone home. Your writing habit is yours alone.

Rich text, your way

Bold, italic, headings, lists. TipTap-powered rich text editor with full keyboard support, spellcheck, and auto-save. Write without thinking about saving.

Calendar navigation

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.

Import from anywhere

Migrate from Mini Diary (JSON), Day One (JSON & TXT), and jrnl (JSON) without losing same-date entries. Bring your history, keep it encrypted.

Export your data

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.

Automatic backups

Fenmark 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.

Writing statistics

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

We don't trust us with your data.

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.

Read the full security model →

At a glance

Quick facts

Short answers for humans and machines: what Fenmark 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

FAQ

What is Fenmark?

Fenmark is a private offline journal app for Windows, macOS, and Linux. It stores entries locally and encrypts them before they are written to disk.

Does Fenmark work fully offline?

Yes. The app does not send entries to cloud services and does not include telemetry. See the privacy policy.

How are journal entries encrypted?

Each entry is encrypted with AES-256-GCM before it is written to disk. See the security model for details.

Which desktop platforms are supported?

Fenmark 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.

Can I import and export journal data?

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.

Is there a mobile app?

Not currently. Fenmark 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

Download Fenmark

All releases are built via GitHub Actions and published with SHA-256 checksums. View all releases →

Windows

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." Fenmark is open source and builds are reproducible from source.

macOS

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/Fenmark.app"
then launch normally. One-time step, no risk.

Linux

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

Release status

Current stable release: v0.8.0.

For the newest installers and checksums, use the GitHub releases page.

Follow the project

Stay in the loop

Fenmark is open source. Watch the repo for releases, star it to show support, or follow along on social media.

Product Hunt profile coming soon.

Support the project

Chip in if it is useful

Fenmark 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

Made with love

Francisco J. Revoredo

Software Engineer based in Linz, Austria. Passionate about privacy, security, and building tools that empower users. When not coding, you can find me gaming, reading, or exploring new ideas.

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