Skip to main content

FileNivo

filenivo

CSV and Excel Upload Error Checker: Validate Your Import File

Import failures waste hours. This free CSV and Excel upload error checker scans your spreadsheet before you import it into WooCommerce, a CRM or another system. It finds duplicate records, missing required fields, bad emails, phone numbers and dates, encoding problems, wrong delimiters and column names that do not match the destination. Your file is checked in your browser and is never uploaded.

Edit destination rules
Drop a CSV or Excel file here or click to choose.
.csv, .tsv, .txt, .xlsx, .xls. Your file is checked in your browser and never uploaded.

All Image Tools

What the CSV error checker finds

  • Duplicate records: repeated rows and repeated values in columns that must be unique, such as SKU or email.
  • Missing required fields: empty cells in columns the destination needs, and required columns missing entirely.
  • Wrong formats: invalid email addresses, phone numbers with letters or too few digits, impossible dates such as 31 February, and prices with currency symbols or comma decimals.
  • Encoding problems: files that are not UTF-8, garbled characters such as “é”, and byte order marks that corrupt the first column name.
  • Delimiter problems: semicolon, tab or pipe separated files, and rows with the wrong number of columns.
  • Column name mismatches: headers that differ from the destination and suggestions such as “Did you mean Regular price?”

How to validate a CSV file before importing

  1. Choose your destination: WooCommerce products or CRM contacts, or set your own rules.
  2. Drop your CSV, TSV or Excel file into the checker.
  3. Fix every error, starting with column names and encoding, then review warnings.
  4. Download the error report, correct the file and check it again until it passes.

WooCommerce product CSV checks

WooCommerce expects exact column names such as Regular price, Sale price, Stock and In stock?. It also expects prices as plain numbers with a dot decimal, a unique SKU for each product and a valid product Type. The checker tests each of these so your product import does not fail halfway through.

CRM contact import checks

Most CRMs reject or silently skip contacts with invalid emails, and they create duplicates when the same email appears twice. The checker validates emails, phone numbers and dates, flags duplicate contacts and makes sure the Email column is present and filled in.

Common CSV import errors and how to fix them

Garbled characters

Re-save the file as CSV UTF-8. In Excel use Save As, then CSV UTF-8 (Comma delimited).

Everything in one column

Your file uses a delimiter your software does not expect. Re-export with commas, or choose the right delimiter when importing.

Dates imported wrongly

Use YYYY-MM-DD. Formats like 03/04/2025 mean different dates in different countries.

Phone numbers turned into 9.23E+11

Format the column as Text before entering numbers, then save again.

Limits of the checker

It checks the first sheet of an Excel workbook. Destination rules are built in for common fields and may not cover custom columns or plugin-specific fields, so use “Edit destination rules” to adjust them. Always run a small test import in your system first.

Frequently Asked Questions

No. The file is read and checked in your browser and never leaves your device.

The file was saved in one encoding and opened as another, usually Windows-1252 read as UTF-8. Re-save it as CSV UTF-8 from Excel or Google Sheets.

The file uses a different delimiter, such as a semicolon, than your system expects. The checker detects the delimiter and tells you which one the file uses.

YYYY-MM-DD is the safest format because it cannot be confused between day-month and month-day order.

Excel converts long numbers to scientific notation. Format the phone column as Text before entering or pasting the numbers, then save again.

Why Use FileNivo?

  • 100% Free to Use
  • No Registration Required
  • Files Never Leave Your Device
  • Super Fast Conversion
  • Works on Any Device