Categories for your expenses

Expenses in a group pile up fast, and at some point the list simply gets hard to scan. Categories change that: every expense can now be assigned to one of ten categories. It shows up as a small badge in the expense list, so you can tell at a glance whether the trip budget went into food or into "entertainment".

You mostly won't have to pick one

The best part: you rarely pick the category yourself. Type "Supermarket run" and the groceries category is selected automatically. "Zugticket nach Berlin" lands on transport. The suggestions work in German and English at the same time, whatever language the interface is set to, and they forgive small typos: "Supermrkt" still counts as a supermarket.

If a suggestion is wrong, tap a different category. If you don't want one at all, clear it. Nothing is forced, and old expenses simply stay uncategorized until someone feels like sorting them.

How this works without us reading your descriptions

Here's the technical part, for those who are interested. Expense descriptions are, as we've mentioned often enough, end-to-end encrypted: your browser encrypts them before they reach us, and the server only ever stores ciphertext. That rules out every "smart" categorizer that runs on a server, because our server can't classify text it can't read.

So the matching happens on your device instead. The app keeps a curated keyword list for each category in the background, and as you type a description, your browser compares the words against that list. Locally, on your device. The description leaves your device encrypted, exactly as before. The only new thing the server learns is the category key itself, plain "groceries", which is stored readable on purpose so the app can filter and chart by it later.

There is no machine learning or AI tooling in this. The whole feature is a word list we tend by hand, plus a bit of edit-distance math for the typos.

Help us tend the word list

A hand-curated keyword list has an obvious weakness: our vocabulary. We think it covers the everyday cases well, in German and English alike. But we haven't eaten at every restaurant, and we don't know what your utilities provider is called.

So if you keep typing an expense that obviously screams a category and DobiSplit stays quiet, tell us. You'll find contact details in the legal notice. We can't learn from your data, since we can't read it, so you are the one feedback channel there is. Adding "Dönerbude" to food & drink is a two-line change, and honestly the kind of bug report we enjoy getting.