Check CSV, TSV, or XLSX data for missing cells, duplicate rows, mixed column types, locale-ambiguous numbers, and potential numeric outliers. Every result is deterministic, reviewable, and kept in your browser.
Add a CSV, TSV, or XLSX file
The file stays in this browser. Legacy .xls, macros, and formula recalculation are not supported.
The source file, inferred types, evidence rows, quality report, saved session, and exports stay in your browser and are excluded from BaseToolbox analytics.
1
Select a worksheet and the number format used by the source.
2
The browser counts missing cells, duplicate typed rows, type evidence, ambiguous numbers, and potential outliers.
3
Inspect severity, affected counts, and source row numbers before exporting CSV, XLSX, JSON, or Markdown.