The journal that writes back.
Write a quick thought or take your time with a full entry. Get a kind reply, talk through a hard moment with The Coach, and see how your mood changes over time.
- Free, no sign-up
- Entries stored on your device
- 3 free AI replies a day
Writing, reflection and mood tracking in one place
Capture what happened, make sense of how you felt, and notice what keeps coming up.
Write in seconds
A feed for one-line thoughts, a full editor for long entries. Markdown, photos, weather and place, and voice-to-text when typing is too slow.
A journal that writes back
Four AI personas reply under each entry: The Friend comforts, The Coach asks CBT questions, The Mentor brings Stoic perspective, The Chronicler sums it up.
From feelings to next steps
Talk an entry through with The Coach, then turn it into two or three small action cards you can tick off.
See your patterns
Mood check-ins become a color calendar and a year map. Weekly reports show your mood curve, streaks and the words that kept coming up.
AI reflection reports
Each week (and month) the AI reads your digests and writes a warm, specific reflection with gentle suggestions — Pro.
Private by design
Entries live in your browser, not on our server. Lock them with a passphrase (AES-GCM), sync end-to-end encrypted, or bring your own AI key.
Start your journal
Choose how you’d like to begin. You can switch between a quick post and the full editor any time.
How much do you want to write?
Try a daily prompt, add a mood, or start with whatever’s on your mind.
From a quick thought to a clearer picture
Start with one sentence. Build a record you can look back on.
Write what’s on your mind
Post one line, answer a prompt, or open the full Markdown editor.
Reflect with an AI companion
Choose a persona for encouragement, CBT questions, Stoic perspective, or a short summary.
Look back at your week
Use the mood calendar and weekly report to spot patterns and revisit what mattered.
Find a way to make journaling yours
Explore prompts, short entries, CBT reflection, mood tracking, and more.
Why people stop journaling — and how DiaryFast fixes it
Journals fail for three reasons: they take too long, the blank page is scary, and nothing comes back. DiaryFast is built against all three.
- Too long? The feed takes one-line posts, like a private timeline. Ten seconds counts.
- Blank page? Three fresh prompts every day — one to reflect, one for gratitude, one to grow.
- Nothing comes back? An AI reply under every entry, a coach for the hard days, and a weekly report that shows you your own patterns.
Quick posts and long-form entries
Use the feed for micro-journaling: a feeling, a win, a worry — with a mood emoji and, if you like, a photo, the weather and where you are. Switch to the long-form editor for real entries, with Markdown, headings, checklists and voice-to-text when your thoughts run faster than your thumbs. More on micro-journaling
Talk it through with a CBT coach
Tap Talk it through on any entry and The Coach starts a short conversation using cognitive behavioral therapy techniques: what happened, what you thought, how you felt, and whether that thought holds up. It names thinking traps gently — catastrophizing, all-or-nothing thinking, mind reading — and ends with two or three small action cards you can tick off. How the CBT journal works
See your patterns
Each mood check-in colors a day on your mood calendar and your year map. The weekly report shows your mood curve, your streak, your best day, mood by weekday and the words that kept coming up — and with Pro, an AI reflection that reads the whole week and writes back. See a weekly reflection
Privacy you can check
Entries are stored in your browser (IndexedDB), not on our servers. Lock them with a passphrase (AES-256-GCM), sync them end-to-end encrypted, or bring your own OpenAI or Anthropic key so AI requests go straight from your browser to the provider. How DiaryFast keeps your journal private
A free journal. More room to reflect with Pro.
Write as much as you like. Upgrade for more AI replies, deeper reports, and encrypted sync.
Free
$0
- Unlimited private entries
- Daily prompts, mood calendar and weekly stats
- 3 AI replies per day
DiaryFast Pro
Pro
$9.99 / month
- Unlimited AI replies and AI reflection reports
- End-to-end encrypted sync and PDF export
- $59 yearly plan or $4.99 24-hour pass available
Questions
Is DiaryFast free?
Yes. Unlimited entries, daily prompts, mood calendar, photos, voice, weather and weekly stats are free, with 3 AI replies a day. Pro ($9.99/month or $59/year) adds unlimited AI, AI reports, encrypted sync and PDF export; a $4.99 pass unlocks everything for 24 hours.
Do I need an account?
No. Open the journal and write — there's nothing to sign up for. An account is only needed if you want encrypted sync between devices or the weekly reminder email.
Can you read my journal?
No. It is stored on your device. When you ask for an AI reply, only that text is sent to the AI and it isn't stored by us. With your own API key, it doesn't pass through us at all.
Does it work on my phone?
Yes. DiaryFast is a web app you can install: in Safari tap Share → Add to Home Screen; in Chrome tap Install. It opens full-screen and works offline.
Is the AI a therapist?
No. The personas are journaling companions that use well-known reflection techniques. They can be wrong and they are not a replacement for professional care. If you are in crisis, call local emergency services or a crisis line (988 in the US and Canada).
