BaseCero
Your money, from zero. Personal finance that lives entirely on your device.
A website that installs as an app on your phone and works offline. It tells you what is really left until your next payday. No server, no accounts, no telemetry.
- Platform
- Browser, on desktop and mobile
- License
- MIT
- Last release
- v1.1.0, Sep 30, 2026
- Web
- basecero.alvarotc.com
- Installs as an app
- PWA, works offline
- Data
- On your device, no server
- Themes
- Light and dark
Screenshots
Every category has its colour and carries it across the app. Aluminium background in light, graphite in dark.
Home Log transaction Transactions Spending by category Net worth Report
What it does
Accounts that follow your payslip, not the calendar.
Net worth
Your total, your accounts, liabilities and savings goals, in a single view.
- Payslip to payslipPeriods run from one payslip to the next, not from the 1st to the 30th. With recurring items, you see what is really left until the next payday.
- Quick entryThe amount on the phone keypad and the category from a grid of colours. Or type "12.50 at the bar with Marta" and the app pulls out the amount, the shop and who you split it with.
- Shared expensesBoth ways: what you owe and what you are owed. Settle up shows the net figure and closes it in one go.
- Categories with limits41 categories on two levels, all editable, each with its colour, and the spending of each one against its limit.
- PDF reportIncome, spending and savings against the previous period. The PDF is generated on your phone.
- Imports your bank CSVThe N26 one is recognised automatically; for any other bank, an assistant asks what each column is.
- Light, dark and two languagesPick a theme or follow your system. In Spanish and English, with the currency and format you choose.
Why it exists
I tried a fair few finance apps and almost all of them failed in the same place: they were free because the business was your data, paid but with your accounts in their cloud, or local but closed. I could not find one that was serverless, account-free, truly offline and open source all at once.
So I built it. It is for people who track their spending by hand and want to stay the owners of their data: if BaseCero disappeared tomorrow, your accounts would still be yours, in a spreadsheet you can open with any program.
Try it
The whole app, right here, in a phone frame. Nothing to install.
- What you enter stays in your browserThere is no server to receive it and no account to create.
- It loads when you askUntil you press the button, the page does not download the app.
- On your phone, as an appOpen basecero.alvarotc.com/app/ and add it to your home screen. It works offline.
How it is built
- JavaScript with no framework and no bundler. SQLite in WebAssembly, no server.
- Local-first: all data lives on your device.
- Installable PWA, works offline.
- No accounts and no telemetry. Dictation is optional and done by the browser; typed, everything stays on the phone.
- Exports to an .xlsx spreadsheet that is yours, plus password-encrypted backups.
- More than 1500 tests with the native Node runner.
- Free software under MIT, code at github.com/alvarotorresc/basecero.
Changelog
- v1.1.0, Sep 30, 2026A full redesign with light and dark themes; a home screen that leads with the balance, and payday; logging by sentence, voice or receipt photo; PDF report; subscription radar; multiple filters and a review of the statement before importing it.
- v1.0.0, Sep 2, 2026The first version to share. BaseCero now installs from any browser and works offline, with no accounts and no cloud.