Clean up a CSV file
On-deviceTrim, fix case, normalize digits and dates in a CSV/Excel file
Clean up a CSV, TSV, XLSX or JSON file right on your device — trim whitespace, fix text case, normalize digits, standardize dates, and drop empty rows or columns, with a live preview before you download. Nothing is uploaded.
Not sure which CSV tool you need? See all six →
About this tool
What you provide
- One CSV, TSV, XLSX or JSON file.
- The transforms to apply: trim whitespace, change letter case, normalize Arabic-Indic digits, standardize dates, drop empty rows or columns.
What you get
- A live preview of the cleaned table before you download.
- The cleaned file as CSV, XLSX, JSON or TSV.
Limits
- The live preview covers the first 100 rows; the transforms apply to the whole file on download.
- Date standardizing handles YYYY-MM-DD and M/D/YYYY dates read as month-first; other formats are left unchanged.
- One file at a time, up to 25 MB, and only the first sheet of an Excel workbook is read.
How to use it
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Choose a file
Tap "Choose a file to clean" or drop a CSV, TSV, XLSX or JSON file onto the dashed area.
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Tick the transforms
Turn on what you need — trim whitespace, normalize Arabic-Indic digits to Western, standardize dates to YYYY-MM-DD, drop empty rows, drop empty columns.
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Set the text case
From the "Text case" menu choose No change, UPPERCASE, lowercase or Title Case, and watch the preview of the first rows redraw with every option you change.
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Apply and download
Under "Apply & download" pick CSV, XLSX, JSON or TSV; the transforms are applied to the whole file as it saves, not only to the preview rows.
Frequently asked questions
How do I clean up messy data in a CSV file?
Upload your CSV or Excel file to the Clean CSV tool, and it trims stray spaces, fixes letter case, and normalizes digits and dates, then gives you a cleaned file to download.
Can it normalize date and number formats?
Yes — it normalizes digits and dates in addition to trimming whitespace and fixing case.
Does this tool upload my spreadsheet anywhere?
No, cleaning happens entirely on your device, so your file never leaves your device.