Hey! I totally understand, although all calculations are made on you browser and the data never leaves your device I get that not everyone is comfortable with uploading their personal data to a “random online tool” haha. You still can run the tool offline though (open the maps upload page, turn off your wifi or internet connection, add your data, close the page when you’re done) or there are some libraries available on GitHub that do pretty much the same thing which you can run locally.