Most journaling apps keep your entries on someone else's computer. They might encrypt them. They might mean well. But the writing — the most personal thing you'll ever type — is still sitting in a database somewhere, behind a login screen you don't control.
I built Cozy because I wanted a journal that didn't have that problem in the first place.
What is a private journaling app?
A private journaling app is a journal that keeps your entries off other people's servers: no account, and no company database holding your writing. Most apps marketed as "private" still upload your entries and rely on encryption to protect them there — the writing still lives on hardware you don't control, held by a company that can be breached or sold. A genuinely private journaling app stores each entry as a file on your own computer, so nothing leaves the machine unless you choose to sync it yourself.
Cozy works this way: every entry is a plain text file in a folder you pick, there's no sign-up, and the app has no server to send your writing to. Privacy here means the absence of a third party, not just a lock on the door.
First, the part most privacy pages leave out: Cozy isn't encrypted
Search for a private journal app and nearly every result will lead with encryption. Cozy doesn't. Your entries are plain text files sitting in a folder you chose, and anyone who can already open that folder on your computer can read them. I'd rather tell you that on the way in than let you find out later.
It isn't an oversight. It's the trade. Encryption inside an app means your journal only exists in a form that one app can read. You're trusting that the company stays around, that the format doesn't change, that the key never gets lost. People lose that bet all the time — a forgotten password, an account that won't recover, an app that shuts down — and when they lose it, the writing is gone for good. There's no reading an encrypted blob without its key.
Plain files can't do that to you. You can open them in any text editor, on any operating system, in twenty years, with or without Cozy. You can back them up, grep them, move them, or read them on a machine that has never heard of me. That's what I mean when I say the journal is yours: not "yours" as a marketing word, but yours in the sense that nothing stands between you and your own writing.
If you want encryption, your computer already does it better
Wanting encryption at rest is completely reasonable, and you can have it — just at the disk level instead of the app level:
- On a Mac: turn on FileVault. It encrypts the whole drive, journal included.
- On Windows: turn on BitLocker, which does the same thing.
- Either one: keep the journal folder inside an encrypted disk image or an encrypted volume, and mount it only when you're writing.
All three protect your journal if the laptop is stolen or the drive is pulled out, and they protect your photos, your documents, and everything else at the same time. Cozy carries on reading the folder exactly as before, because to Cozy it's still just a folder. And when you want your entries out, they're still plain files — the encryption is a layer around them, not a cage they live in.
What none of this protects you from is someone using your computer while it's unlocked and you're away from it. Neither does app-level encryption, in practice, once the app is open. Lock your screen. That one habit does more for a private journal than any feature list.
What "private" actually means here
Cozy has no backend, so there's nowhere for your entries to be uploaded. There's no sign-up and no profile. The app doesn't phone home to count taps or words or sessions. And your journal is just a folder — if you want it on two devices, you put the folder in iCloud or Dropbox yourself (iCloud Drive if one of those devices is your iPhone).
So the privacy on offer isn't "we encrypted it and promise not to peek." It's that there's no we. No server holding your writing, no account linking it to your name, no analytics pipeline, no future policy change, no acquisition. The only copy is the one on your machine, and the only thing standing between you and it is the password you already use to log into your computer.
Your entries are files you can read
Every Cozy entry is a plain text file in a folder on your computer. You can open that folder right now in your file manager. You can open any entry in any text editor. They're not locked inside a database.
If the app disappears tomorrow, you still have your journal. That's the point.
Privacy and AI
There's a quieter privacy problem in most journaling apps right now: AI. A lot of them have added writing assistants, summaries, or chat features, and most of those don't run on your computer — they send your entries to OpenAI, Anthropic, or another model provider. Even if the journaling app itself never reads what you wrote, those companies do, because the app is really just a wrapper around their API.
Cozy doesn't have any AI features at all. Your entries aren't sent to a model, because there is no model. If you ever want AI in the loop, you get to make that decision yourself — which tool, which entries, on what terms — instead of the app deciding for you. I wrote about this in more detail in why Cozy doesn't have AI.
Plain files outlive the app
The other half of staying private is staying readable. Plain text files are the one format that every app and every operating system already knows how to open. If Cozy is ever gone, or you want to move your journal somewhere else, the files just work. No export, no migration tool, no format that only one company understands.
Why this matters
A private journal is the place you write the things you wouldn't say out loud. Worries, frustrations, the small things you're working through. If that writing is sitting in someone else's database, it isn't really private. It's private until something changes about the company holding it.
Cozy fixes that by taking the company out of the loop, and it does it without handing you a new thing to lose. Files on your disk, encrypted by your disk if you want them to be, readable by you forever either way.
What about syncing across devices?
Cozy doesn't run a sync service. Because the journal is just a folder, you can put it inside iCloud, Dropbox, Syncthing, or any similar tool and it syncs the same way your photos and documents do. You decide which service to trust — or trust none of them and keep the folder on one machine.
- iCloud or Dropbox: the easy route, but worth knowing your entries then sit on that company's servers in whatever form it stores them.
- Syncthing: syncs device to device, so no company's servers are involved at all.
- No sync: keep the folder local. The only copy is the one on your machine.
Related reading: an offline journaling app, a journaling app for plain text files, and a journaling app without a subscription.