Anticode Open builder

Build a private journaling app with prompts, entries that stay put, and a way out

People keep a diary for themselves, and many hesitate to write freely in an app that stores it on someone else's server. Anticode can build a journaling app where entries are saved only in the browser on your device: no account, no upload. That privacy comes with a responsibility the app should make easy: exporting your writing, so a cleared browser or a lost phone doesn't take years of it with it.

Updated · By the Anticode team

Writing first, features second

The editor is where people spend their time, so it deserves the care. A wide, quiet writing area with a readable body size, the date at the top, autosave as they type (with a small "Saved" indicator, not a button), and nothing else on screen while writing. Word count can be shown on request. Simple formatting such as headings, bold and lists is enough; the more toolbar there is, the less it feels like a notebook.

Prompts that help rather than nag

A blank page stops many people. Offer one prompt above the editor that can be skipped or swapped, drawn from a list you write or approve. Group them so people can choose a mode:

Gratitude
Three things that went well today, and why. The fixed three-line format is what makes a gratitude journal app quick to keep up.
Reflection
What took most of my energy today? What would I do differently?
Morning pages
No prompt, a target of a few hundred words, written straight after waking.
Weekly review
Shown on Sundays: what moved forward, what's waiting, what to drop.

Prompts are text in the app, so you can rewrite them with a change request. A journaling coach or a therapist building one for clients can supply their own set, and if they want to adjust prompts later without a rebuild, ask for them to come from a CMS collection they edit in the Anticode dashboard; the app reads it but can't change it.

Finding old entries

  • Calendar of days with entries, so gaps and streaks are visible without a streak counter.
  • Search across all entries, which runs instantly in the browser.
  • Tags added by the writer, and filters by tag or prompt type.
  • On this day entries from a month or a year ago, which many diarists find the most rewarding part.

Where entries live, and how to keep them

Anticode apps run in a sandbox with no network, so nothing written in this diary app is sent anywhere: not to a server, not to the site owner, not to Anticode. Entries are stored in the browser's local storage on that device. A few megabytes holds a lot of plain text, though photos aren't a good fit for that space.

Local-only storage means the writer is the backup. The export routine should be a first-class feature, not a settings afterthought:

  1. One-tap export to a file: plain text or Markdown for reading anywhere in decades' time, and JSON for importing back into the app.
  2. Import on a new device, merging rather than overwriting.
  3. A visible "last exported" date on the home screen.
  4. Print a month or a year as a tidy book-style page.

Installing the published app to a phone's home screen makes it open like any other diary app, still with nothing leaving the device.

Describing it to Anticode

"A private journal app. Distraction-free editor with autosave, light formatting, date heading. One prompt above the editor from four modes: gratitude, reflection, morning pages, weekly review (Sundays). Calendar, full-text search, tags, and On this day. Export as Markdown and JSON, import JSON, last-exported date on the home screen, print a month. Warm, paper-like design, one sans-serif font, dark mode." Related: mood tracker, notes app and the habit tracker.

Limits

  • No encryption you control. Entries are stored as the browser stores them. A passcode screen can stop a casual glance, but anyone with access to the unlocked device and some knowledge could read the data. Say this honestly in the app.
  • No sync or cloud backup. Phone and laptop each have their own diary unless you move a file between them.
  • No voice or photo capture. There's no microphone or camera access.
  • No AI reflections. AI can't run inside the app, so there are no generated summaries or replies to entries.

Questions people ask

Is a journaling app like this really private?

Entries never leave the device through the app. The remaining risks are local: someone using your unlocked device, or the browser data being cleared.

Can two people share a journal?

Not live. Each device has its own entries. A shared family or travel journal would need a server.

What happens if I clear my browser history?

Clearing history alone may not remove site data, but clearing site data or cookies for all sites usually does. Export first.