CSV Add Row Numbers & Index

Insert an auto-incrementing row number, sequence index, or ID column into CSV data.

How It Works & Processing Standards

Insert an auto-incrementing row number, sequence index, or ID column into CSV data.

Your input data is never sent to any server and is securely processed on your device.

Current Limits

  • Desktop max file size: 50MB
  • Mobile max file size: 20MB

CSV Add Row Numbers & Index is a 100% free, browser-based online utility. All calculations and file conversions run locally inside your browser (Local-First) without sending data to remote servers, keeping your documents and inputs strictly private.

How to Use CSV Add Row Numbers & Index

  1. 1
    Paste CSVEnter your CSV table.
  2. 2
    Set Index OptionsSpecify column name (e.g. id, row_num) and starting number (e.g. 1 or 0).
  3. 3
    Export TableCopy or download the CSV with the added index column.

Examples

Add ID Column
Input: name,department Alice,Engineering Bob,Design
Result: id,name,department 1,Alice,Engineering 2,Bob,Design

Common Use Cases

  • Adding artificial primary key IDs before importing datasets into SQL databases
  • Creating line item numbers for invoice or order tables
  • Preserving original row order before running sorting operations

Frequently Asked Questions (FAQ)

Can I customize the starting number and step interval?

Yes, you can set custom start indices (e.g. 1001) and step intervals (e.g. increment by 1 or 10).

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