Import CleanerImport Cleaner

Clean CSV/Excel

Clean CSV and Excel files: a quick 5-step tutorial

Need to clean a CSV or Excel file without macros or scripts? Import Cleaner analyses your file right in the browser, flags errors row by row and hands back a clean sheet ready to import.

Clean CSV Excel online: duplicates, emails, invisible spaces, amounts, phone numbers, dates and encoding fixed in minutes.

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Tutorial: how to clean a CSV or Excel file

  1. 1

    1. Upload the file

    Drop your .csv, .xlsx or .xls into the upload zone. The delimiter (comma, semicolon, tab, pipe) is detected automatically.

  2. 2

    2. Map the columns

    Match your headers to the expected fields, rename a column, delete the ones you do not need, then save a template for future imports.

  3. 3

    3. Detect the errors

    The engine reviews the most common data issues and shows a clear report, with a dedicated tab for custom formats (dates, decimals, textual blanks).

  4. 4

    4. Fix

    Apply fixes in one click or edit cells by hand in the interactive grid. Every error stays traceable row by row.

  5. 5

    5. Export the clean sheet

    Review the full final preview, then download the cleaned file as CSV or Excel.

Application preview

Import Cleaner interface for cleaning a CSV or Excel file: upload, map, detect, fix and export steps
The cleaning flow: file upload on the left, raw preview on the right, 5-step progress on top.

What gets cleaned automatically

  • Strict, email-based and ID-based duplicates
  • Emails normalised to lowercase
  • Trailing spaces and invisible characters
  • Non-numeric amounts and currency symbols
  • Phone numbers and missing leading zeros
  • Ambiguous dates and custom date formats
  • Broken accented encoding (ANSI to UTF-8)
  • Inconsistent nulls (NULL, NaN, -, N/A)
  • Scientific notation and long product codes
  • Unclosed quotes and inconsistent rows

Frequently asked questions

How do I clean a CSV or Excel file for free?
Open Import Cleaner, drop your file, apply the suggested fixes and download the clean sheet. No account needed.
Is my data uploaded to a server?
No. Analysis and fixes run inside your browser, so the file never leaves your machine.
How large can my file be?
Large files are processed in batches to avoid freezes, and a warning appears when you approach the usual Excel limits.

Clean CSV Excel online: duplicates, emails, invisible spaces, amounts, phone numbers, dates and encoding fixed in minutes.

Clean my file now