Clean CSV, TSV, and XLSX data locally with a reviewable change log. Trim text, normalize whitespace and headers, remove duplicates by selected keys, preview rejected rows, undo, and export without uploading the file.
The source file, preview, operation manifest, and export remain in your browser. BaseToolbox does not receive file contents, headers, cell values, or filenames through analytics.
1
Choose a worksheet and select only the cleaning operations you want to apply.
2
Compare before and after samples, inspect the operation log, and review any rows marked for removal.
3
Save the operation manifest, keep the source available for undo, and download the cleaned CSV or XLSX.