SignalSheet is a local-first CSV profiler for operators, analysts and small teams who need a fast answer before building a dashboard. Load a CSV in the browser to inspect missing cells, duplicates, inferred types, dominant categories and exploratory outliers, then export a Markdown or JSON summary and a cleaned CSV. The source file stays on the device. A free checklist is available, with a paid self-serve tool and an optional 24-hour custom analysis.
Messy spreadsheets often hide the first useful signal behind missing values, inconsistent types and duplicate rows. I built SignalSheet to make that first audit quick, transparent and private: no server upload, no API key and no invented case studies. The goal is a small tool that helps someone decide what to investigate next.