Transform wide data to tidy (long) format
This tool processes all data entirely in your browser — no information is ever uploaded to external servers, ensuring complete privacy and security. When you load a CSV file, it is parsed directly in JavaScript and stored temporarily in memory. If you save your datasets, they are securely stored locally using IndexedDB, a browser-based storage system that keeps your data accessible across sessions. Because everything runs client-side, the tool works offline once loaded, and your data never leaves your device.