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CSV Data Cleaner BETA

PapaParse-powered CSV editor: type detection, 1-click auto-clean, applied steps with undo, data quality panel, number/date conversion. Runs 100% locally in your browser.

Drop a CSV file here or click to browse

.csv only · optional header row · runs 100% in your browser

Auto-Clean removes empty rows, duplicates, and fixes typos/casing. Remove Empty Rows deletes any row that contains an empty cell. Remove Duplicates deletes only rows that are identical on every column. Fill Empty Cells replaces blanks using Fill Down/Up, the most common value, or a custom value. Use the column headers to clean specific columns.

This tool is in Beta. Please verify your results. If you find a bug, contact us via the icon above.
How to use this tool?
  • Load a CSV file.
  • Select the correct Email/Phone columns.
  • Use "1-Click Auto-Clean" to remove empty rows and duplicates and fix typos/casing (you confirm what it changes in the preview first).
  • Use "Remove Empty Rows" to delete rows with empty cells, or "Fill Empty Cells" to fill them (Fill Down/Up, most-common value, or your own value).
  • Use the "Column Clean" menu on headers for specific formatting (Uppercase, Capitalize, etc.).
  • Use "Replace All" to find and replace specific text across all cells.
  • Use "Sequence ID" to renumber rows.
  • Use "Undo" to revert the last action.

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What is the CSV Data Cleaner?

It brings a spreadsheet-style workflow to messy CSV files. The header row is never treated as data: every column is scanned for its type (Number, Date or Text) using only real rows. The Data Quality panel reports exact empties and unique values per column, while the Applied Steps panel records every operation you perform so you can undo the last three in sequence.

  • 1-Click Auto-Clean removes empty rows and duplicates and fixes probable typos and inconsistent capitalization (confirmed by you in a preview dialog).
  • Probable typos such as “Baki” vs “Bakı” are flagged as Manual Review Required and are never changed for you.
  • Convert to Number keeps invalid text untouched (never 0) and flags each bad cell with an Error badge.
  • Convert to YYYY-MM-DD detects the dominant date format (US vs EU vs ISO), normalizes valid dates and flags invalid dates.

How to use the CSV Data Cleaner?
  1. Drop a .csv file into the upload area (or click to browse). Use the “Use First Row as Headers” toggle as needed.
  2. Review the Data Quality panel (computed in a Web Worker) for exact empty/valid percentages and unique value counts.
  3. Click 1-Click Auto-Clean (removes empty rows and duplicates, fixes typos/casing) or open a column’s Clean menu for Trim, Capitalize, Convert to Number or Convert to YYYY-MM-DD.
  4. Check the Applied Steps panel; press Undo (last 3) to reverse operations in sequence or Clear History to start fresh.
  5. Use "Replace" to find and replace specific text across all cells.
  6. Download the cleaned CSV and inspect the Change Report for exact counts, including conversion errors.

Frequently Asked Questions (FAQ)

Is the CSV Data Cleaner free?

Yes, completely free with no signup and no file uploads.

Are my files uploaded to a server?

No. Parsing runs with PapaParse and heavy analysis runs in a Blob Web Worker inside your browser. Nothing ever leaves your device.

How large a file can it clean?

Optimized for a few tens of thousands of rows; heavy steps (column transforms and auto-clean analysis) above 5,000 rows run in a Web Worker so the page stays responsive.

Does auto-clean fix possible typos?

Yes. 1-Click Auto-Clean removes empty rows and duplicates and fixes probable typos and casing. Because removing rows is destructive, it first shows a preview dialog where you confirm each category before anything changes.

What manual cleaning tools are available?

Remove Empty Rows, Remove Duplicates, Fill Empty Cells (fill down/up, most-common value or a custom value), and a per-column menu: Trim Whitespace, UPPERCASE, lowercase, Capitalize, Convert to Number and Convert to YYYY-MM-DD.

Can I undo my changes?

Yes. The Applied Steps panel undoes the last three operations and a toolbar Undo reverts the latest change; Reset clears all applied steps.