Data & documents tools

Read, validate and convert common documents and data — all processed in your browser.

Local processing: your data is processed in your browser and never sent to Numelto or any external service.

Check the format and control letter/digit of a Spanish DNI, NIE or NIF, or calculate the letter from the digits.

Check whether an IBAN has a valid structure and checksum, for any country, or calculate a Spanish IBAN from a CCC.

Compare two CSV or Excel files and detect added, removed and modified rows by key column.

Open and browse an Excel file (XLSX/XLS) or CSV directly in your browser, nothing to install.

Stack several CSV/Excel files into one, or join them by a shared column, like a JOIN.

Remove duplicate rows from a CSV or Excel file by one or more columns, keeping the first or the last.

Split a CSV or Excel file by row count, by column value, or into several equal parts.

Convert a pasted CSV or a CSV/Excel file to JSON, using the header row as each property's name.

Convert an array of JSON objects to CSV, ready to open in Excel or Google Sheets.