Compare CSV Online

Paste two CSV or TSV datasets. See row-level and cell-level differences in a table view.

🔒 100% private — runs entirely in your browser

or try sample data

What is CSV Diff?

CSV Diff is a free tool for comparing two CSV or TSV files with a visual table-based diff. It highlights added, removed, and modified rows and shows cell-level changes within modified rows. Perfect for data migration testing, spreadsheet comparison, and database export validation.

  • Table-based view — see differences in a familiar spreadsheet-like format.
  • Cell-level comparison — modified rows show exactly which cells changed.
  • Custom delimiters — supports comma, tab, semicolon, and pipe delimiters.
  • Header row support — toggle to use the first row as column headers.
  • Privacy-first — all processing happens in your browser.

How to Use CSV Diff

Compare CSV data in three steps — paste, configure, and inspect.

1. Paste Your CSV Data

Enter the original CSV in the left panel and the updated version in the right. You can paste directly from spreadsheets, database exports, or .csv files.

2. Configure Header & Delimiter

Indicate whether the first row contains headers and select the delimiter (,, \t, |, or custom). Click Compare to start the diff.

3. Inspect the Table Diff

Results appear in a table view with added rows in green, removed rows in red, and modified cells highlighted in yellow. Scan columns quickly to find exactly what changed.

Common Use Cases

Spreadsheet Version Comparison

Export two versions of a Google Sheets or Excel file as CSV, then paste them here to see which rows and cells were modified between versions.

Database Export Validation

Run the same query against staging and production, export the results as CSV, and diff them to verify data consistency across environments.

ETL Pipeline Output Verification

Compare the output of an ETL pipeline before and after a code change to ensure that transformations produce identical results. Catch rounding errors, missing rows, or column mismatches.

Frequently Asked Questions

How do I compare two CSV files online?

Paste or type your CSV data into the left and right panels, then click Compare. The tool parses each CSV, aligns the rows, and highlights added, removed, and modified cells with color coding. You can change the delimiter if your data uses tabs, semicolons, or pipes.

What is a CSV diff?

A CSV diff is a structured comparison of two CSV (Comma-Separated Values) datasets. Unlike a plain text diff, a CSV diff understands rows and columns — it compares cell values and highlights exactly which fields changed between two versions of tabular data.

Is my CSV data safe when using this tool?

Yes. All processing happens in your browser using client-side JavaScript. Your CSV data is never uploaded to any server, so it's safe to compare spreadsheets containing sensitive business data, financial records, or personal information.

What delimiters are supported?

The tool supports comma (,), tab, semicolon (;), and pipe (|) delimiters. You can select the delimiter that matches your data format. This makes it compatible with CSV exports from Excel, Google Sheets, databases, and most data tools.

Can I compare data exported from Excel or Google Sheets?

Yes. Export your spreadsheet as CSV (File → Download → CSV in Google Sheets, or Save As → CSV in Excel), then paste the contents into the tool. The comparison works with any standard CSV format.

Does this tool handle headers in CSV files?

Yes. If the 'First row is header' option is enabled, the tool treats the first row as column names and uses them to align and label the comparison. This makes it easy to see which columns changed.