black triangle

Local-first encrypted storage.

Free forever. No accounts. No tracking. No servers.

Download How it works

Open for all the world to see.

Runs offline, wherever you are.

Earth

Technical. Nothing else.

Argon2id key derivation

Memory-hard KDF. Your passphrase is the only thing that unlocks the database.

ChaCha20-Poly1305 AEAD

Every record is encrypted and authenticated. Tampering is detected, not tolerated.

Write-ahead log

Crash-safe. Append-only WAL with CRC32C checksums and idempotent recovery.

Separate lock files

Single-writer enforced with a lock file. Works on Windows without breaking antivirus.

Open export format

Dump everything to a human-readable JSON document. Never locked in.

No network. Ever.

The app never opens a socket. No updates, no pings, no phone-home.

Download

Choose your platform.

Windows
.exe, portable
Unsigned — SmartScreen warning expected
Windows
.exe, installer
Unsigned — SmartScreen warning expected
Linux (.deb)
Debian / Ubuntu
Linux (.rpm)
Fedora / RHEL
Android
.apk, signed
Click to download (41 MB)
Web (PWA)
Open in browser
"Add to Home Screen" on iOS

How it works

01

Local-first

All data lives on your device. The database is a single file you own and can copy, back up, or delete.

02

Nothing collected

No accounts, no telemetry, no crash reports. We don't know you exist, and we like it that way.

03

Open format

Export everything to JSON at any time. If this project disappears tomorrow, your data lives on.

Where does your data live?

On your device. Always.

01

No server

This site only delivers HTML, CSS, JS, and a WebAssembly module. It never receives your data. There is no cloud, no account, no sync, no telemetry.

02

One encrypted file

The database is a single file (or a localStorage entry in the PWA) on your machine, encrypted with Argon2id + ChaCha20-Poly1305. The passphrase is the only key.

03

No recovery channel

Because there is no server, there is no "password reset". If you forget the passphrase, the data is lost. Back it up. Export it to JSON. Own it.

Same app. Everywhere.

How to run it on each platform.

01

Windows

Download the .exe — portable for no-install, or installer for Start Menu entry. Your data lives in %APPDATA%\local.blacktriangle\, encrypted with your passphrase.

02

Linux

.deb for Debian/Ubuntu (sudo dpkg -i), .rpm for Fedora/RHEL (sudo rpm -i). Data is stored in your home directory, one encrypted file per database.

03

Android

Download the signed .apk and install it. Allow "unknown sources" if asked. Everything stays in the app sandbox — no network, no accounts, no sync.

04

Web (PWA)

Open /pwa/ in any modern browser. Optionally "Add to Home Screen" to install it like a native app. Data stays in the browser's encrypted storage.