CSV Validator Online

Check pasted or uploaded CSV for delimiter mistakes, ragged rows, duplicate headers, empty rows, BOM markers and quote escaping before importing it elsewhere.

Format CSV (clean and preview) Open the Excel to CSV converter

Need to reformat valid data instead of checking errors? Open the CSV formatter.

Convert Excel files to CSV before validating rows, headers, and delimiters.

Ready

Issues

    Preview

    Import-ready CSV

    Find short rows, extra columns and header mismatches before sending a file to a CRM, database import or spreadsheet workflow.

    Delimiter checks

    Auto-detect comma, semicolon, tab and pipe data, then flag files that appear to be opened with the wrong separator.

    Header validation

    Compare the first row with an expected header list and detect duplicate column names that can break downstream imports.

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    CSV Validator

    Check delimiter consistency, quoting, duplicate headers, ragged rows, and selected import requirements.

    Input
    CSV text or a local CSV file plus validation rules.
    Output
    A row-aware validation report and preview.
    Real limitations
    Passing these structural checks does not prove that business values, dates, identifiers, or a downstream import schema are correct.
    Privacy and data handling
    CSV text or a local CSV file plus validation rules is processed in this browser tab. Convertr does not receive or store it; closing or reloading the page clears the working state unless the tool explicitly offers a local download.

    How to use this tool

    1. Provide CSV text or a local CSV file plus validation rules in the tool controls.
    2. Choose the settings that affect a row-aware validation report and preview, then run the tool.
    3. Review a row-aware validation report and preview before copying or downloading it.

    Common failure modes

    Unclosed quotes, duplicate headings, inconsistent field counts, or invalid encoding appear with actionable row information.

    Useful example

    Validate an inventory export and find that row 18 has six fields while the five-column header defines five.