CSV Cleaner
Clean, preview and export CSV data.
Clean CSV headers, trim values and remove duplicate rows in your browser. Review issues, then export with your chosen delimiter, encoding and line endings.
- Prepare your input
Choose the relevant options using the controls below.
- Run your task
Adjust the controls below and inspect the preview.
- Use the result
Check the result, then use the available copy or download controls.
Preview
Rows: 0
Operations
Column numbers start at 1. Operations run from top to bottom; numbers refer to the columns at that step.
Value and date conversion are off by default. Opting in to value normalization also changes 1/0 to true/false.
- Remove leading and trailing spaces from cells.
- Choose case style and deduplicate header names.
- Remove only completely empty rows and columns.
- Select columns to treat as a unique key.
- Remove BOM markers; malformed quotes are reported, not guessed.
- yes/no → true/false; NA/null → empty or explicit null.
- Convert explicit-offset timestamps to UTC. Date-only, ambiguous and invalid values stay unchanged.
- Infer int/float/bool/date/string per column.
- Literal or regex across columns.
- Split by delimiter or merge with a template.
- Hide or reorder columns before export.
- See row errors with reasons and export a report.
Issues
Export
CSV Cleaner
Prepare a CSV export for import into a spreadsheet or database. Select the delimiter, input encoding and whether the first row contains headers, then enable only the cleaning operations you need. You can normalize headers, trim values, remove empty rows or columns and deduplicate on selected columns.
For example, to keep one customer record per email address, select the email column as the duplicate key and choose whether to keep the first or last record. Inspect the preview and issues before exporting. Wrong encoding can be corrected by rereading an uploaded file with its actual encoding; the tool cannot reconstruct characters already lost before upload. Malformed quotes are reported rather than guessed.
Features
- Normalize headers and trim values; remove empty rows or columns.
- Remove duplicates using selected key columns and a first/last record rule.
- Apply optional value/date transformations, find-and-replace and required-field checks.
- Preview the result and export CSV with a delimiter, LF/CRLF and supported encoding.
How to use
- Upload a CSV file or paste CSV text; check its delimiter, encoding and header setting.
- Open Operations and enable the required steps. For an email list, select the email column as the deduplication key.
- Run Clean CSV, then inspect Preview and Issues for unintended changes or missing required values.
- Choose export settings and download the cleaned CSV. Keep a copy of the original data for comparison.