Four AI personas, four kinds of help
- 🤗 The Friend — validates first, celebrates small wins, sounds like a real friend texting back.
- 🧭 The Coach — uses CBT: separates facts from thoughts, spots thinking traps, asks one Socratic question at a time and helps you plan a small next step.
- 🏛️ The Mentor — Stoic perspective in the spirit of Marcus Aurelius and Epictetus: what is within your control, and what isn't.
- 📜 The Chronicler — distils an entry into one sentence and a few tags, so your archive stays searchable.
Replies like comments on a post
Each entry gets its reply underneath, like a comment on a post — short, specific to what you wrote, never a lecture. Want more? Ask another persona, or open Talk it through for a real back-and-forth.
Weekly AI reflection
On Sunday, open your weekly report: the AI reads short digests of your entries and writes The shape of your week, what kept coming up, wins worth noticing, two or three gentle suggestions and one question to carry into next week (Pro).
Your words stay yours
Entries live in your browser. When you ask for a reply, the entry is sent over HTTPS to the AI and the answer streams back; we don't store or log it. Prefer full control? Paste your own OpenAI or Anthropic key and your browser talks to the provider directly.
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
Which AI model does DiaryFast use?
Replies come from OpenAI's API. With your own key you can choose an OpenAI or Anthropic (Claude) model in Settings.
How many AI replies are free?
3 a day on the free plan, unlimited with Pro or with your own API key.
Can the AI see my old entries?
Only what you send it: the entry you ask about, its conversation, or — for weekly reports — short digests of that week. It has no memory between requests.
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).