Local first
Every entry, photo, mood and AI reply is stored in your browser's IndexedDB. Nothing is uploaded when you write. You can export a full JSON backup at any time and import it on another device.
Passphrase lock (AES-256-GCM)
Turn on the lock in Settings and your entries are encrypted at rest with a key derived from your passphrase (PBKDF2-SHA-256, 310,000 iterations). The passphrase is never stored or sent. Forget it and the entries are unrecoverable — by anyone.
End-to-end encrypted sync
With Pro, sync your journal between phone and computer. Each entry is encrypted in your browser with your sync passphrase before upload; our server only stores ciphertext and can't decrypt it. Delete your account and every server copy goes with it.
AI without handing over your diary
AI replies are processed on request and not stored by us. With bring your own key, your browser sends the entry straight to OpenAI or Anthropic under your own account — DiaryFast never sees the request. No ads, no trackers, no analytics scripts inside the journal.
Free and Pro
Writing, prompts, mood tracking, photos, weather and your weekly stats are free forever, with 3 AI replies a day. Pro adds unlimited AI, AI reports, encrypted sync and PDF export. Or try everything for a day with the $4.99 pass.
| Feature | Free | Pro |
|---|---|---|
| Journal entries (short posts and long form) | Unlimited, on your device | Unlimited |
| Daily prompts, mood check-ins, mood calendar & year map | ✓ | ✓ |
| Photos, weather and place on entries | ✓ | ✓ |
| Voice to text | 60 seconds per take | Unlimited |
| Voice conversation (replies read aloud, hands-free answers) | ✓ | ✓ |
| AI replies & CBT coaching (Friend, Coach, Mentor, Chronicler) | 3 per day | Unlimited (fair use) |
| Your own OpenAI / Anthropic key (BYOK) | ✓ no daily limit | ✓ |
| Weekly report: mood curve, keywords, streaks | ✓ | ✓ |
| AI weekly & monthly reflection reports | — | ✓ |
| Your month as a PDF book (entries, photos, AI replies) | Preview | ✓ |
| End-to-end encrypted sync between devices | — | ✓ (monthly or yearly) |
| Passphrase lock (AES-GCM) & JSON backup | ✓ | ✓ |
Questions
What happens if I clear my browser data?
The journal on that device is deleted. Export a backup or turn on encrypted sync to keep a copy.
Where are synced entries stored?
On our server, as AES-GCM ciphertext. We can see how many items and bytes you store, never their content.
Is my API key safe?
It's stored only in your browser and sent only to the provider you chose. Use a key with a spending limit.
DiaryFast is a journaling and self-reflection tool. It is not therapy and doesn't diagnose or treat any condition. If you are in crisis, contact local emergency services or a crisis line (US & Canada: 988).