CSV Cleaner
Fix a messy CSV in seconds: trim stray whitespace, drop duplicate and empty rows and columns, normalize semicolon/tab delimiters to standard commas, strip BOM, and flag the exact rows with an inconsistent column count. Free, no signup.
Don't have a file handy? Try a sample messy CSV
Need to clean many files at once?
Batch mode cleans a whole folder of CSVs with the same settings — one-time purchase, yours forever.
Questions
Does my file get uploaded anywhere?
No. The cleaning runs entirely in your browser. Your file is never sent to a server — this page makes no network requests with your data, so it keeps working even after you go offline once the page has loaded.
What exactly does it change?
With the default options it trims leading and trailing whitespace from every cell, removes fully empty rows, and removes exact duplicate rows. It also normalizes the delimiter to commas (it auto-detects comma, semicolon, tab, or pipe) and strips a byte-order mark (BOM) if one is present. "Drop empty columns" is an optional checkbox, off by default. Any option can be turned off before you clean.
Does it handle commas and line breaks inside quoted fields?
Yes. It reads the file with a proper CSV parser that understands quoted
fields, escaped double-quotes (""), and newlines inside quotes,
so a value like "Smith, Jr." stays in a single cell.
What does the column-count warning mean?
After cleaning, the tool checks whether every row has the same number of fields and lists the row numbers of any that differ from the most common count. Ragged rows are a frequent silent cause of failed imports, so it flags them — but it never alters the data in those rows.
Is there a file-size limit?
Because everything runs in your browser, the practical limit is your device's memory rather than a fixed cap. Exports of tens of thousands of rows clean near-instantly; very large files may take longer.
What is batch mode?
Batch mode is a one-time purchase that cleans many CSV files at once with the same settings, instead of one at a time. It uses the same in-browser engine, so your files still never leave your computer.