The Locked Diary Online
The Sealed Journal vs Penzu.
A lock on their server, or no server at all.
Penzu is the classic online diary, and it has earned its longevity: sign in from anywhere, write, and your entries follow you. Its pitch has always been privacy — locks, passwords, and on higher tiers, encryption.
But Penzu's privacy is a promise kept by infrastructure: your diary lives on their servers, behind your account, protected by their implementation of their policy. That can be done well, and perhaps it is. You are still trusting a company with the most unguarded text you produce.
The Sealed Journal makes a different offer: there is no server to trust. Entries are encrypted in your browser with AES-256-GCM and stored on your machine. Nothing is uploaded, so nothing can be breached, subpoenaed, or quietly mined. Not "military-grade" — no target at all.
The Facts, Side by Side
| Penzu | The Sealed Journal | |
|---|---|---|
| Pricing model | Freemium with paid tiers | One-time purchase |
| Current price | Pro: $4.99 / month · Pro (annual): $19.99 / year · Pro+: ~$49.99 / year | One purchase: $24 (rising to $29) once |
| Free tier | Free online diary with limited features | No — a live demo, then one price |
| Platforms | Web, iOS, Android | Any modern browser, any operating system |
| Account required | Yes — Account required | No — no account, ever |
| Cloud sync | Required — Entries live on Penzu's servers | No sync, no server — a single offline HTML file |
| Encryption | Not a client-side passphrase model | AES-256-GCM client-side, PBKDF2 at 600,000 iterations |
Checkout shows current prices; tiers verified via app-store listing.
Penzu prices checked 11 August 2026. Source: penzu.com/pro. If you find a figure out of date, tell us and we'll correct it.
The Typewriter Experience
The cursor stays. The text moves.
In Write mode, your cursor remains exactly at the centre of the screen. The page rises up to meet it. Past words fade into soft shadow at the edges, leaving the present sentence in clear focus. Switch to Read mode and the entry flattens into an evenly lit document — the fade is for writing; the flat light is for returning.
Radical Privacy & Encryption
AES-256-GCM, in your browser, with a key only you derive.
- ·PBKDF2 key derivation at 600,000 iterations — the OWASP 2024 recommendation. Existing journals upgrade transparently on first unlock.
- ·No accounts, no telemetry, no analytics, no cookies, no third-party scripts.
- ·IndexedDB storage with a localStorage fallback. Encrypted before it touches the disk.
- ·The file is not minified. You can read the source. We'd rather you trust it than us.
What It Does Not Do
- ✕No word counts chasing you across the screen.
- ✕No formatting toolbar wrestling your thoughts into neatness.
- ✕No cloud sync. No distant servers. Your words stay yours.
- ✕No social sharing. Your vulnerability is not content.
- ✕No AI assistant finishing your sentences.
- ✕No streak counters. No guilt. No gamification.
- ✕No subscriptions. No mood trackers. No noise.
Licensing & Gift Copy
One purchase covers up to three of your personal devices. It also includes a second untouched copy of the file — meant to be given to one person you trust. Lifetime updates. 30-day, no-questions refund. If you run a clinic, school, or workplace and want a copy for everyone, ask us about a site licence.
One Purchase. Yours Forever.
The price is $24 today. It will become $29.
One-time payment
Get The Sealed JournalQuestions
Penzu says my entries are encrypted. Isn't that the same?
Encryption on their servers still means your diary lives on their servers, reachable through your login. Ours never leaves your machine, and the key is derived from a passphrase that never leaves it either.
Can I write from any device, like Penzu?
Your license covers three personal devices, and the file goes wherever you copy it. What you give up is automatic anywhere-access; that convenience is precisely the cloud we removed.
Is there a free tier?
No — there is a live demo, and then one price. Free hosted diaries are paid for somehow; we'd rather charge you $24 than wonder.
More in Comparisons
See all →The Sealed Journal vs journaling in Google Docs.
Free, familiar, and never quite private-feeling.
The Sealed Journal vs Day One.
Both are journals. They're built on opposite assumptions about where your writing should live.
The Sealed Journal vs journaling in Notion.
Notion is a brilliant tool for organising work. It is a strange place to put your inner life.
The Sealed Journal vs Apple Notes.
Apple Notes is the path of least resistance. The Sealed Journal is the path that takes the journaling seriously.
The Sealed Journal vs Obsidian for journaling.
Obsidian is for building a second brain. The Sealed Journal is for emptying the first one for a moment.
The Sealed Journal vs a paper notebook.
Paper is excellent. It also can't be locked, searched, or carried in the pocket of a thousand future devices.
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Your journal lives on your machine. Not someone else's.
No syncing, no servers, no "your data is safe with us." Local storage, encrypted, yours.
Core
An encrypted journal where the passphrase never leaves your device.
AES-256-GCM with PBKDF2 key derivation at 600,000 iterations — the OWASP 2024 recommendation. Done in your browser, not on a server.
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A private, offline journal that asks nothing of you.
One file. One password. Yours forever. No accounts, no cloud, no algorithms reading your three-in-the-morning thoughts.
Answers
Are journaling apps actually private?
A bedroom with the door ajar.
The cursor will be there when you return.
Centered. Blinking. Patient.
Start Writing