🧹 CSV Cleaner

Paste CSV or TSV and apply dedupe, sort, blank-row removal, cell trim, header normalization, column extraction, and line-ending unification in one shot. RFC 4180 quote support.

✅ 100% free, no signup, runs entirely in your browser

🔒 About Privacy

・All processing happens entirely in your browser
・Your CSV data is never sent to any server
・No logs, no history, no database

⚙️ Input Settings

Delimiter

Header Row

Line Endings

🧹 Cleaning Options

Remove duplicate rows Remove blank rows Trim cell whitespace Remove trailing line whitespace Normalize header to snake_case (lowercase) Quote all fields

Dedup Key Columns (blank = full match)

1-based column numbers or header names, comma separated

Extract Columns (blank = all)

Only the specified columns are kept

Sort Column

Order

Sort Type

Top N Rows

Input CSV / TSV

Output Preview (first 100 rows)

🔗 Related Tools

📖 How to Use

1

Paste CSV or TSV

Paste your data into the left input. The delimiter can be auto-detected or chosen manually.
2

Choose cleaning options

Tick options like dedupe, sort, blank-row removal, and column extraction. Dedup keys and sort columns accept either 1-based numbers or header names.
3

Copy or download the result

The cleaned output appears on the right. Use the Copy button or Download (.csv / .tsv) to export.

❓ FAQ

How are duplicate rows detected?

By default rows are duplicates only when every cell matches. If you specify dedup key columns, rows are duplicates when those columns match. The first occurrence is kept.

Are quoted commas and newlines preserved correctly?

No. The parser follows RFC 4180, so commas, newlines, and escaped quotes ("") inside double-quoted fields are handled correctly.

Can it handle large CSV files?

All processing runs in the browser. Tens of thousands of rows work fine; very large files may briefly slow the browser. Preview is capped at 100 rows for performance.

🐛 Found a bug or issue with this tool?

Free to use, no signup. Even just the steps to reproduce are helpful. Reports go directly to the operator and help us fix issues.