A private diary app.

Turn on the rain, talk to the AI for a few minutes, and the day's entry is written.

Free plan, no card required. Sign in for 30 Credits refreshed every day.

Open today's entry

Unlimited entries

Write as much, as often as you like. Free users have no entry limit.

Every device

Open a browser and write. Phone, tablet, laptop all work. iOS native app coming soon.

Stop anytime

Close it half-written; pick up where you left off next time.

Rain sound + rain curtain

The rain loops in the background. Four sliders for amount, speed, fog, and refraction tune it the way you want.

AI guidance

When you don't know what to write, the AI asks a question narrow enough to answer. After the conversation, the day's entry is composed from what you said.

One day, end to end

Open the tab and the rain is already running. Say three sentences about the day. The AI asks one thing back, you answer, and the entry appears under today's date. Flip the calendar to any past day to read it again, or turn it into a poster and post it. Nothing to install, nothing to name, nothing to file.

Choose your plan.

Rainku is free by default. Pro adds monthly Credits, higher Effort levels, and voice-guided conversations. Prices as of 2026-07-02.

Free

Start writing — no card needed.

Unlimited entries
Rain sound + rain curtain
30 Credits refreshed daily
Poster export
Cross-device sync

Pro Monthly

$8 / month

Everything in Free
3,000 Credits per month
Higher Effort levels unlocked
Voice-guided conversations
Priority support

Pro Annual

$80 / year

About 17% off monthly

Everything in Pro Monthly
36,000 Credits per year

Credits are the unit for AI work — a chat turn, a composed entry, a poster. A turn costs more at a higher Effort level, so a quick check-in and a long session aren't billed the same. Unused monthly Credits reset each cycle; Credits you buy outright never expire.

See plans

Built for these moments.

Rainku is built for people who want to write today down. Pick the moment you're in, A private journal, your first time journaling, or a journal that looks the way you want — or just write, without picking one.

Wherever you write.

Rainku runs in any browser. Nothing to install on Mac, Windows, or Linux. The same page works on phone and tablet. Served in six languages: English, 简体中文, 日本語, 한국어, ไทย and Bahasa Indonesia. An iOS app is in the works.

Why people choose Rainku.

They want a writing space with rain as the background, not the noise of notifications and algorithms.
They want to say it out loud, but not to a person. Rainku turns the conversation into an entry.
They want a record nobody else sees and nothing else trains on.

How to start.

Journaling is one of the few things time keeps proving useful. Every time you write, a past day is seen again.

1
Open it
Sign in at Rainku.com and open your journal in the rain.
2
Say a few things
Type into the chat box, or tap the mic. The AI asks a few follow-ups that keep up with your train of thought.
3
Look back / share
Next time you come back, flip the calendar to a past day. If you want to share it, generate a poster.

Start writing.