Duplicate invoices, invalid IBANs, repeated customer emails: Blockema finds them in your Excel or CSV in seconds, before they cost you money. Drop in a file and it suggests rules for every column. Add your own by dragging blocks (no formulas), including rules that compare rows or depend on another column. Jump to each error, fix it and download the corrected file with its formatting intact. Runs in your browser, so your file never leaves your computer. Same rules, same result, every time.