WhatTheDuck is a free-to-use tool that allows you to run SQL queries on your CSV files right in your browser. No data is sent anywhere. We've leveraged the power of DuckDB over WASM to make this possible. Do try it out and hit us with any feedback.
I almost gave up checking this out, as the window remained an empty white page. Disable ad-blockers to check if they were the problem. They were not. Then suddenly the UI popped up. It looked interesting. But without source code to check, or a privacy policy I wouldn't just try it out.