Number every row in your CSV data instantly. Everything runs in your browser — your data never leaves your device.
Client-side only — your data stays private.
Numbered CSV will appear here...Load CSV and click Add Row Numbers to see results
Three simple steps to add row numbers to your CSV.
Paste your CSV data directly into the input area or upload a file.
Choose a column name, set the starting number, and decide if numbers go first or last.
Preview the numbered data and copy to clipboard or download as a new CSV file.
A CSV Row Numberer is a utility that adds sequential row numbers or custom IDs as a new column to your CSV files. Whether you need to track rows in a dataset, create unique identifiers, or simply add a numbering column for reference, this tool makes it fast and easy.
This tool lets you customize the column name, starting number, and column position. Unlike spreadsheet software, it works entirely in your browser with no data upload, making it ideal for sensitive datasets.
Data tracking
Keep track of row positions when sorting or filtering.
Reference points
Create easy references for discussing specific rows.
Database import
Add auto-incrementing IDs for database imports.
Verification
Verify row counts match between source and destination.
Paste or upload your CSV, configure the column name, start number, and position in the sidebar, then click Add Row Numbers. The result appears immediately in the output panel.
Yes. You can start numbering from any integer — 0, 1, 100, 1000, or any other value.
You can choose to place the row number column either as the first column (before all other columns) or as the last column (after all other columns).
Yes. You can insert row numbers at the beginning, end, or any custom position in the CSV. You can also customize the column header and starting number.
For a complete CSV workflow, explore our other free tools:
All processing happens in your browser. Your data never leaves your device.