100% in your browser

capi.tax runs entirely on your own computer. Your broker export and your transaction data never travel to a server, and there is no account to create. Everything that happens with your figures happens in the browser tab in front of you.

Nothing is uploaded

When you select your CSV file, the browser reads it directly from your computer. It is not sent anywhere. The whole calculation — currency conversion, FIFO matching, the tax summary — is performed locally and shown back to you on the same page.

Because your data never leaves your device, there is no copy of it on any server, no database that could be breached, and nothing for us to store, share, or sell. We simply never receive it.

It works offline

The first time you open capi.tax, your browser downloads the application itself: the page and the calculation engine. After that, the calculation runs without an internet connection. You can disconnect from the network, load your file, and still get your full result. The only thing that needs the internet is fetching official Deutsche Bundesbank exchange rates, and those are cached once retrieved.

Your data is cleared when you leave

Your transactions live only in the browser's memory while you work. When you close the tab or navigate away, that memory is released and the data is gone. There is nothing to delete afterwards, because nothing was kept.

For your protection, the session also clears itself after a period of inactivity. If you step away, your data is removed automatically rather than sitting open on screen.

A practical note

Since nothing is stored, your results are not kept for you between visits. If you want to keep a copy, export your report before you close the page. To move your work to another device, export it and open it there — there is no cloud sync, by design.

See it for yourself

You can verify all of this. Open your browser's developer tools, switch to the network tab, and process a file. You will see the application and exchange rates load, but no upload of your data. Or load the page once, disconnect from the internet, and confirm the calculation still runs.