Free CSV cleaning tools

Each tool runs entirely in your browser, so your data is never uploaded. Free for files up to 5,000 rows.

Remove Duplicates

Delete duplicate rows from a CSV or Excel file in seconds. Exact or key-column matching, a full change log, and your data never leaves your browser.

Normalize Dates

Fix mixed date formats in a CSV: 03/04/2024, 4 March 2024 and 2024-03-04 become one format. Detects US vs European order per column. Free, in-browser.

Validate Emails

Find and quarantine invalid email addresses in a CSV before you import it. Lowercases and trims emails, flags bad formats. Private: runs in your browser.

Trim Whitespace

Remove leading, trailing and double spaces from every cell in a CSV or Excel file, and drop blank rows. Free, instant and private — nothing is uploaded.

Merge CSV Files

Combine multiple CSV files into one, even when columns are in a different order. Optional duplicate removal. Free, private and runs in your browser.

CSV to Excel Cleaner

Clean up a messy CSV — duplicates, blank rows, spacing, headers, dates — and save it as an Excel-ready file. Private, in-browser CSV to XLSX cleaner.

Fix CSV Encoding

Repair garbled characters like Ã©, â€™ and Ã¼ in a CSV and convert Windows-1252 files to UTF-8. Free, private, runs entirely in your browser.